Some source files state copyright dates that are earlier than the
last modification of the file. Change the copyright year to 2022 in
all such cases.
Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220930224549.3503434-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch just updates comments throughout the IPA code.
Transaction state is now tracked using indexes into an array rather
than linked lists, and a few comments refer to the "old way" of
doing things. The description of how transactions are used was
changed to refer to "operations" rather than "commands", to
(hopefully) remove a possible ambiguity.
IPA register offsets and fields are now handled differently as well,
and the register documentation is updated to better describe the
code.
A few minor updates to comments were made (e.g., adding a missing
word, fixing a typo or punctuation, etc.).
Finally, the local macro atomic_dec_not_zero() is no longer used, so
it is deleted.
Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220930224527.3503404-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Define the fields for the ENDP_INIT_DEAGGR, ENDP_INIT_RSRC_GRP,
ENDP_INIT_SEQ, ENDP_STATUS, and ENDP_FILTER_ROUTER_HSH_CFG, and
IPA_IRQ_UC IPA registers for all supported IPA versions.
Create enumerated types to identify fields for these IPA registers.
Use IPA_REG_FIELDS() and IPA_REG_STRIDE_FIELDS() to specify the
field mask values defined for these registers, for each supported
version of IPA.
Use ipa_reg_encode() and ipa_reg_bit() to build up the values to be
written to these registers, remove an inline function and all the
*_FMASK symbols that are now no longer used.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Define the fields for the ENDP_INIT_MODE, ENDP_INIT_AGGR,
ENDP_INIT_HOL_BLOCK_EN, and ENDP_INIT_HOL_BLOCK_TIMER IPA
registers for all supported IPA versions.
Create enumerated types to identify fields for these IPA registers.
Use IPA_REG_STRIDE_FIELDS() to specify the field mask values defined
for these registers, for each supported version of IPA.
Change aggr_time_limit_encode() and hol_block_timer_encode() so they
take an ipa_reg pointer, and use those register's fields to compute
their encoded results. Have aggr_time_limit_encode() take an IPA
pointer rather than version, to match hol_block_timer_encode().
Use ipa_reg_encode(), ipa_reg_bit(), and ipa_reg_field_max() to
manipulate values to be written to these registers, remove the
definitions of the various inline functions and *_FMASK symbols that
are now no longer used.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Define the fields for the ENDP_INIT_CTRL, ENDP_INIT_CFG, ENDP_INIT_NAT,
ENDP_INIT_HDR, and ENDP_INIT_HDR_EXT IPA registers for all supported
IPA versions.
Create enumerated types to identify fields for these IPA registers.
Use IPA_REG_STRIDE_FIELDS() to specify the field mask values defined
for these registers, for each supported version of IPA.
Move ipa_header_size_encoded() and ipa_metadata_offset_encoded() out
of "ipa_reg.h" and into "ipa_endpoint.c". Change them so they take
an additional ipa_reg structure argument, and use ipa_reg_encode()
to encode the parts of the header size and offset prior to writing
to the register. Change their names to be verbs rather than nouns.
Use ipa_reg_encode(), ipa_reg_bit, and ipa_reg_field_max() to
manipulate values to be written to these registers, remove the
definition of the no-longer-used *_FMASK symbols.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Define the fields for the FLAVOR_0, IDLE_INDICATION_CFG,
QTIME_TIMESTAMP_CFG, TIMERS_XO_CLK_DIV_CFG and TIMERS_PULSE_GRAN_CFG
IPA registers for all supported IPA versions.
Create enumerated types to identify fields for these IPA registers.
Use IPA_REG_FIELDS() to specify the field mask values defined for
these registers, for each supported version of IPA.
Use ipa_reg_bit() and ipa_reg_encode() to build up the values to be
written to these registers. Use ipa_reg_decode() to extract field
values from the FLAVOR_0 register.
Remove the definition of the no-longer-used *_FMASK symbols.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Create the ipa_reg_clkon_cfg_field_id enumerated type, which
identifies the fields for the CLKON_CFG IPA register. Add "CLKON_"
to a few short names to try to avoid name conflicts. Create the
ipa_reg_route_field_id enumerated type, which identifies the fields
for the ROUTE IPA register.
Use IPA_REG_FIELDS() to specify the field mask values defined for
these registers, for each supported version of IPA.
Use ipa_reg_bit() and ipa_reg_encode() to build up the values to be
written to these registers rather than using the *_FMASK
preprocessor symbols.
Remove the definition of the now unused *_FMASK symbols.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Create a new function that returns a register descriptor given its
ID. Change ipa_reg_offset() and ipa_reg_n_offset() so they take a
register descriptor argument rather than an IPA pointer and register
ID. Have them accept null pointers (and return an invalid 0 offset),
to avoid the need for excessive error checking. (A warning is issued
whenever ipa_reg() returns 0).
Call ipa_reg() or ipa_reg_n() to look up information about the
register before calls to ipa_reg_offset() and ipa_reg_n_offset().
Delay looking up offsets until they're needed to read or write
registers.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Expose two inline functions that return the offset for a register
whose ID is provided; one of them takes an additional argument
that's used for registers that are parameterized. These both use
a common helper function __ipa_reg_offset(), which just uses the
offset symbols already defined.
Replace all references to the offset macros defined for IPA
registers with calls to ipa_reg_offset() or ipa_reg_n_offset().
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Both aggr_time_limit_encode() and hol_block_timer_encode() figure
out how to encode a millisecond time value so it can be programmed
into a register. Rearranging them a bit can make their similarity
more obvious, with both taking essentially the same form.
To do this:
- Return 0 immediately in aggr_time_limit_encode() if the
microseconds value supplied is zero.
- Reverse the test at top of aggr_time_limit_encode(), so we
compute and return the Qtime value in the "true" block,
and compute the result the old way otherwise.
- Open-code (and eliminate) hol_block_timer_qtime_encode() at the
top of hol_block_timer_encode() in the case we use Qtimer.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Create a new function ipa_qtime_val() which returns a value that
indicates what should be encoded for a register with a time field
expressed using Qtime. Use it to factor out common code in
aggr_time_limit_encoded() and hol_block_timer_qtime_val().
Rename aggr_time_limit_encoded() and hol_block_timer_qtime_val() so
their names are both verbs ending in "encode". Rename the "limit"
argument to the former to be "milliseconds" for consistency.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Starting with IPA v4.5, replication is done differently from before,
and as a result the "replication" portion of the how the sequencer
is specified must be zero.
Add a check for the configuration data failing that requirement, and
only update the sesquencer type value when it's supported.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In ipa_endpoint_init_hdr(), as well as ipa_endpoint_init_hdr_ext(),
a top-level automatic variable named "offset" is used to represent
the offset of a register.
However, deeper within each of those functions is *another*
definition of a local variable with the same name, representing
something else. Scoping rules ensure the result is what was
intended, but this variable name reuse is bad practice and makes
the code confusing.
Fix this by naming the inner variable "off". Use "off" instead of
"checksum_offset" in ipa_endpoint_init_cfg() for consistency.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When a GSI transaction completes, ipa_endpoint_trans_complete() is
eventually called. That handles TX and RX completions separately,
but ipa_endpoint_tx_complete() is a no-op.
Instead, have ipa_endpoint_trans_complete() return immediately for a
TX transaction, and incorporate code from ipa_endpoint_rx_complete()
to handle RX transactions.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The trans_tre_max field of the IPA endpoint structure is only used
to limit the number of fragments allowed for an SKB being prepared
for transmission. Recognizing that, rename the field skb_frag_max,
and reduce its value by 1.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Each GSI channel has a TLV FIFO of a certain size, specified in the
configuration data for an AP channel. That size dictates the
maximum number of TREs that are allowed in a single transaction.
The only way that value is used after initialization is as a limit
on the number of TREs in a transaction; calling it "tlv_count"
isn't helpful, and in fact gsi_channel_trans_tre_max() exists to
sort of abstract it.
Instead, rename the channel->tlv_count field trans_tre_max, and get
rid of the helper function. Update a couple of comments as well.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the (possibly compound) pages used for receive buffers are
freed using __free_pages(). But according to this comment above the
definition of that function, that's wrong:
If you want to use the page's reference count to decide
when to free the allocation, you should allocate a compound
page, and use put_page() instead of __free_pages().
Convert the call to __free_pages() in ipa_endpoint_replenish_one()
to use put_page() instead.
Fixes: 6a606b9015 ("net: ipa: allocate transaction in replenish loop")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently the (possibly compound) page used for receive buffers are
freed using __free_pages(). But according to this comment above the
definition of that function, that's wrong:
If you want to use the page's reference count to decide when
to free the allocation, you should allocate a compound page,
and use put_page() instead of __free_pages().
Convert the call to __free_pages() in ipa_endpoint_trans_release()
to use put_page() instead.
Fixes: ed23f02680 ("net: ipa: define per-endpoint receive buffer size")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In ipa_endpoint_modem_exception_reset_all(), a high estimate was
made of the number of endpoints that need their status register
updated. We only used what was needed, so the high estimate didn't
matter much.
However the next few patches are going to limit the number of
commands in a single transaction, and the overestimate would exceed
that. So count the number of modem TX endpoints at initialization
time, and use it in ipa_endpoint_modem_exception_reset_all().
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since the beginning gsi_trans_commit_wait_timeout() has existed to
provide a way to allow waiting a limited time for a transaction
to complete. But that function has never been used.
In fact, there is no use for this function, because a transaction
committed to hardware should *always* complete. The only reason it
might not complete is if there were a hardware failure, or perhaps a
system configuration error.
Furthermore, if a timeout ever did occur, the IPA hardware would be
in an indeterminate state, from which there is no recovery. It
would require some sort of complete IPA reset, and would require the
participation of the modem, and at this time there is no such
sequence defined.
So get rid of the definition of gsi_trans_commit_wait_timeout(), and
update a few comments accordingly.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Don't assume that a 500 microsecond time limit should be used for
all receive endpoints that support aggregation. Instead, specify
the time limit to use in the configuration data.
Set a 500 microsecond limit for all existing RX endpoints, as before.
Checking for overflow for the time limit field is a bit complicated.
Rather than duplicate a lot of code in ipa_endpoint_data_valid_one(),
call WARN() if any value is found to be too large when encoding it.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new flag for AP receive endpoints that indicates whether
a "hard limit" is used as a criterion for closing aggregation.
Add comments explaining the difference between "hard" and "soft"
aggregation limits.
Pass a flag to ipa_aggr_size_kb() so it computes the proper
aggregation size value whether using hard or soft limits. Move
that function earlier in "ipa_endpoint.c" so it can be used
without a forward-reference.
Update ipa_endpoint_data_valid_one() so it validates endpoints whose
data indicate a hard aggregation limit is used, and so it reports
set aggregation flags for endpoints without aggregation enabled.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new Boolean flag for RX endpoints defining whether HOLB drop
is initially enabled or disabled for the endpoint. All existing AP
endpoints should have HOLB drop disabled.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
All elements of the default endpoint configuration are used in the
code when programming an endpoint for use. But none of the other
configuration data is ever needed once things are initialized.
So rather than saving a pointer to *all* of the configuration data,
save a copy of only the endpoint configuration portion.
This will eventually allow endpoint configuration to be modifiable
at runtime. But even before that it means we won't keep a pointer
to configuration data after when no longer needed.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rename the just-moved data structure types to drop the "_data"
suffix, to make it more obvious they are no longer meant to be used
just as read-only initialization data. Rename the fields and
variables of these types to use "config" instead of "data" in the
name. This is another small step meant to facilitate review.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If we program an RX endpoint to have no header (header length is 0),
header-related endpoint configuration values are meaningless and are
ignored.
The only case we support that defines a header is QMAP endpoints.
In ipa_endpoint_init_hdr_ext() we set the endianness mask value
unconditionally, but it should not be done if there is no header
(meaning it is not configured for QMAP).
Set the endianness conditionally, and rearrange the logic in that
function slightly to avoid testing the qmap flag twice.
Delete an incorrect comment in ipa_endpoint_init_aggr().
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If an RX endpoint receives packets containing status headers, and a
packet in the buffer is not dropped, ipa_endpoint_skb_copy() is
responsible for wrapping the packet data in an SKB and forwarding it
to ipa_modem_skb_rx() for further processing.
If ipa_endpoint_skb_copy() gets a null pointer from build_skb(), it
just returns early. But in the process it doesn't record that as a
dropped packet in the network device statistics.
Instead, call ipa_modem_skb_rx() whether or not the SKB pointer is
NULL; that function ensures the statistics are properly updated.
Fixes: 1b65bbcc9a ("net: ipa: skip SKB copy if no netdev")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The aggregation byte limit for an endpoint is currently computed
based on the endpoint's receive buffer size.
However, some bytes at the front of each receive buffer are reserved
on the assumption that--as with SKBs--it might be useful to insert
data (such as headers) before what lands in the buffer.
The aggregation byte limit currently doesn't take into account that
reserved space, and as a result, aggregation could require space
past that which is available in the buffer.
Fix this by reducing the size used to compute the aggregation byte
limit by the NET_SKB_PAD offset reserved for each receive buffer.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rather than tracking the number of receive buffer transactions that
have been submitted without a doorbell, just track the total number
of transactions that have been issued. Then ring the doorbell when
that number modulo the replenish batch size is 0.
The effect is roughly the same, but the new count is slightly more
interesting, and this approach will someday allow the replenish
batch size to be tuned at runtime.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replenishing is now solely driven by whether transactions are
available for a channel, and it doesn't really matter whether
we replenish before or after we deliver received packets to the
network stack.
Replenishing before delivering the payload adds a little latency.
Eliminate that by requesting a replenish after the payload is
delivered.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We no longer use the replenish_backlog atomic variable to decide
when we've got work to do providing receive buffers to hardware.
Basically, we try to keep the hardware as full as possible, all the
time. We keep supplying buffers until the hardware has no more
space for them.
As a result, we can get rid of the replenish_backlog field and the
atomic operations performed on it.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Create a new function that returns true if all transactions for a
channel are available for use.
Use it in ipa_endpoint_replenish_enable() to see whether to start
replenishing, and in ipa_endpoint_replenish() to determine whether
it's necessary after a failure to schedule delayed work to ensure a
future replenish attempt occurs.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rather than determining when to stop replenishing using the
replenish backlog, just stop when we have exhausted all available
transactions.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When replenishing, have ipa_endpoint_replenish() allocate a
transaction, and pass that to ipa_endpoint_replenish_one() to fill.
Then, if that produces no error, commit the transaction within the
replenish loop as well. In this way we can distinguish between
transaction failures and buffer allocation/mapping failures.
Failure to allocate a transaction simply means the hardware already
has as many receive buffers as it can hold. In that case we can
break out of the replenish loop because there's nothing more to do.
If we fail to allocate or map pages for the receive buffer, just
try again later.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Decide whether the doorbell should be signaled when committing a
replenish transaction in the main replenish loop, rather than in
ipa_endpoint_replenish_one(). This is a step to facilitate the
next patch.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Three spots call ipa_endpoint_replenish(), and just one of those
requests that the backlog be incremented after completing the
replenish operation.
Instead, have the caller increment the backlog, and get rid of the
add_one argument to ipa_endpoint_replenish().
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
A transaction failure only occurs if no more transactions are
available for an endpoint. It's a very cheap test.
When replenishing an RX endpoint buffer, there's no point in
allocating pages if transactions are exhausted. So don't bother
doing so unless the transaction allocation succeeds.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The replenish_saved field keeps track of the number of times a new
buffer is added to the backlog when replenishing is disabled. We
don't really use it though, so there's no need for us to track it
separately. Whether replenishing is enabled or not, we can simply
increment the backlog.
Get rid of replenish_saved, and initialize and increment the backlog
where it would have otherwise been used.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow RX endpoints to have differing receive buffer sizes. Define
the receive buffer size in the configuration data, and use that
rather than IPA_RX_BUFFER_SIZE when configuring the endpoint.
Add verification in ipa_endpoint_data_valid_one() that the receive
buffer specified for AP RX endpoints is both big enough to handle at
least one full packet, and not so big in an aggregating endpoint
that its size can't be represented when programming the hardware.
Move aggr_byte_limit_max() up in "ipa_endpoint.c" so it can be used
earlier in the file without a forward-reference.
Initially we'll just keep the 8KB receive buffer size already in use
for all AP RX endpoints..
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We have seen cases where an endpoint RX completion interrupt arrives
while replenishing for the endpoint is underway. This causes another
instance of replenishing to begin as part of completing the receive
transaction. If this occurs it can lead to transaction corruption.
Use a new flag to ensure only one replenish instance for an endpoint
executes at a time.
Fixes: 84f9bd12d4 ("soc: qcom: ipa: IPA endpoints")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Define a new replenish_flags bitmap to contain Boolean flags
associated with an endpoint's replenishing state. Replace the
replenish_enabled field with a flag in that bitmap. This is to
prepare for the next patch, which adds another flag.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In ipa_endpoint_replenish(), if an error occurs when attempting to
replenish a receive buffer, we just quit and try again later. In
that case we increment the backlog count to reflect that the attempt
was unsuccessful. Then, if the add_one flag was true we increment
the backlog again.
This second increment is not included in the backlog local variable
though, and its value determines whether delayed work should be
scheduled. This is a bug.
Fix this by determining whether 1 or 2 should be added to the
backlog before adding it in a atomic_add_return() call.
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Fixes: 84f9bd12d4 ("soc: qcom: ipa: IPA endpoints")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
One quirk for certain versions of IPA is that endpoint DELAY mode
does not work properly. IPA DELAY mode prevents any packets from
being delivered to the IPA core for processing on a TX endpoint.
The AP uses DELAY mode when the modem crashes, to prevent modem TX
endpoints from generating traffic during crash recovery. Without
this, there is a chance the hardware will stall during recovery from
a modem crash.
To achieve a similar effect, a GSI FLOW_CONTROLLED channel state
was created. A STARTED TX channel can be placed in FLOW_CONTROLLED
state, which prevents the transfer of any more packets. A channel
in FLOW_CONTROLLED state can be either returned to STARTED state, or
can be transitioned to STOPPED state.
Because this operates on GSI channels, two generic commands were
added to allow the AP to control this state for modem channels
(similar to the ALLOCATE and HALT channel commands).
Previously the code assumed this quirk only applied to IPA v4.2.
In fact, channel flow control (rather than endpoint DELAY mode)
should be used for all versions *starting* with IPA v4.2.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In ipa_endpoint_skb_copy(), a new socket buffer structure is
allocated so that some data can be copied into it. However, after
doing this, if the endpoint has a null netdev pointer, we just drop
free the socket buffer.
Instead, check endpoint->netdev pointer first, and just return early
if it's null. Also return early if the SKB allocation fails, to
avoid the deeper indentation in the normal path.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
During setup, ipa_endpoint_program() programs each endpoint with
various configuration parameters. One of those registers defines
whether to drop packets when a head-of-line blocking condition is
detected on an RX endpoint. We currently assume this is disabled;
instead, explicitly set it to be disabled.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The head-of-line block (HOLB) drop timer is only meaningful when
dropping packets due to blocking is enabled. Given that, redefine
the interface so the timer is specified when enabling HOLB drop, and
use a different function when disabling.
To enable and disable HOLB drop, these functions will now be used:
ipa_endpoint_init_hol_block_enable(endpoint, milliseconds)
ipa_endpoint_init_hol_block_disable(endpoint)
The existing ipa_endpoint_init_hol_block_enable() becomes a helper
function, renamed ipa_endpoint_init_hol_block_en(), and used with
ipa_endpoint_init_hol_block_timer() to enable HOLB block on an
endpoint.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Calling ipa_cmd_pipeline_clear() after stopping the channel
underlying the AP<-modem RX endpoint can lead to a deadlock.
This occurs in the ->runtime_suspend device power operation for the
IPA driver. While this callback is in progress, any other requests
for power will block until the callback returns.
Stopping the AP<-modem RX channel does not prevent the modem from
sending another packet to this endpoint. If a packet arrives for an
RX channel when the channel is stopped, an SUSPEND IPA interrupt
condition will be pending. Handling an IPA interrupt requires
power, so ipa_isr_thread() calls pm_runtime_get_sync() first thing.
The problem occurs because a "pipeline clear" command will not
complete while such a SUSPEND interrupt condition exists. So the
SUSPEND IPA interrupt handler won't proceed until it gets power;
that won't happen until the ->runtime_suspend callback (and its
"pipeline clear" command) completes; and that can't happen while
the SUSPEND interrupt condition exists.
It turns out that in this case there is no need to use the "pipeline
clear" command. There are scenarios in which clearing the pipeline
is required while suspending, but those are not (yet) supported
upstream. So a simple fix, avoiding the potential deadlock, is to
stop calling ipa_cmd_pipeline_clear() in ipa_endpoint_suspend().
This removes the only user of ipa_cmd_pipeline_clear(), so get rid
of that function. It can be restored again whenever it's needed.
This is basically a manual revert along with an explanation for
commit 6cb63ea6a3 ("net: ipa: introduce ipa_cmd_tag_process()").
Fixes: 6cb63ea6a3 ("net: ipa: introduce ipa_cmd_tag_process()")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The head-of-line blocking timer should only be modified when
head-of-line drop is disabled.
One of the steps in recovering from a modem crash is to enable
dropping of packets with timeout of 0 (immediate). We don't know
how the modem configured its endpoints, so before we program the
timer, we need to ensure HOL_BLOCK is disabled.
Fixes: 84f9bd12d4 ("soc: qcom: ipa: IPA endpoints")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
