This is another great example of trainwreck engineering:
commit 2646a0e529 (ARM: edma: Add EDMA crossbar event mux support)
added support for using EDMA on peripherals which have no direct EDMA
event mapping.
The code compiles and does not explode in your face, but that's it.
1) Reading an u16 array from an u32 device tree array simply does not
work. Even if the function is named "edma_of_read_u32_to_s16_array".
It merily calls of_property_read_u16_array. So the resulting 16bit
array will have every other entry = 0.
2) The DT entry for the xbar registers related to xbar has length 0x10
instead of the real length: 0xfd0 - 0xf90 = 0x40.
Not a real problem as it does not cross a page boundary, but
wrong nevertheless.
3) But none of this matters as the mapping never happens:
After reading nonsense edma_of_read_u32_to_s16_array() invalidates
the first array entry pair, so nobody can ever notice the
braindamage by immediate explosion.
Seems the QA criteria for this code was solely not to explode when
someone adds edma-xbar-event-map entries to the DT. Goal achieved,
congratulations!
Not really helpful if someone wants to use edma on a device which
requires a xbar mapping.
Fix the issues by:
- annotating the device tree entry with "/bits/ 16" as documented in
the of_property_read_u16_array kernel doc
- make the size of the xbar register mapping correct
- invalidating the end of the array and not the start
This convoluted mess wants to be completely rewritten as there is no
point to keep the xbar_chan array memory and the iomapping of the xbar
regs around forever. Marking the xbar mapped channels as used should
be done right there.
But that's a different issue and this patch is small enough to make it
work and allows a simple backport for stable.
Cc: stable@vger.kernel.org # v3.12+
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
edma header defines DMA_COMPLETE, this causes issues as commit adfedd9a32 move
DMA_SUCCESS to DMA_COMPLETE. edma should properly namespace its defines and
needs a future fix
Reported-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
HWMOD removal for MMC is breaking edma_start as the events are being manually
triggered due to unused channel list not being clear.
The above issue is fixed by reading the "dmas" property from the DT node if it
exists and clearing the bits in the unused channel list if the dma controller
used by any device is EDMA. For this purpose we use the of_* helpers to parse
the arguments in the dmas phandle list.
Also introduced is a minor clean up of a checkpatch error in old code.
Reviewed-by: Sekhar Nori <nsekhar@ti.com>
Reported-by: Balaji T K <balajitk@ti.com>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Nishanth Menon <nm@ti.com>
Cc: Pantel Antoniou <panto@antoniou-consulting.com>
Cc: Jason Kridner <jkridner@beagleboard.org>
Cc: Koen Kooi <koen@dominion.thruhere.net>
Signed-off-by: Joel Fernandes <joelf@ti.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Manual trigger for events missed as a result of splitting a
scatter gather list and DMA'ing it in batches. Add a helper
function to trigger a channel incase any such events are missed.
Signed-off-by: Joel Fernandes <joelf@ti.com>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
EDMA supports a cross bar which provides ability
to mux additional events into physical channels
present in the channel controller.
This is required when the number of events present
in the system are more than number of available
physical channels.
Changes by Joel:
* Split EDMA xbar support out of original EDMA DT parsing patch
to keep it easier for review.
* Rewrite shift and offset calculation.
Suggested-by: Sekhar Nori <nsekhar@ti.com>
Suggested by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Joel A Fernandes <joelagnel@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
[nsekhar@ti.com: fix checkpatch errors and a minor coding improvement]
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Adds support for parsing the TI EDMA DT data into the required EDMA
private API platform data. Enables runtime PM support to initialize
the EDMA hwmod. Enables build on OMAP.
Changes by Joel:
* Setup default one-to-one mapping for queue_priority and queue_tc
mapping as discussed in [1].
* Split out xbar stuff to separate patch. [1]
* Dropped unused DT helper to convert to array
* Fixed dangling pointer issue with Sekhar's changes
[1] https://patchwork.kernel.org/patch/2226761/
Signed-off-by: Matt Porter <mporter@ti.com>
[nsekhar@ti.com: fix checkpatch errors, build breakages. Introduce
edma_setup_info_from_dt() as part of that effort]
Signed-off-by: Joel A Fernandes <joelagnel@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Use devm_ioremap_resource instead of reques_mem_region()/ioremap(),
devm_request_irq() instead of request_irq() and kzalloc() calls to
devm_kzalloc().
This ensures more consistent error values and simplifies error paths.
Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
[nsekhar@ti.com: add missing err.h include]
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Fix build on OMAP, the irqs are undefined on AM33xx.
These error interrupt handlers were hardcoded as disabled
so since they are unused code, simply remove them.
Signed-off-by: Matt Porter <mporter@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Move mach-davinci/dma.c to common/edma.c so it can be used
by OMAP (specifically AM33xx) as well.
Signed-off-by: Matt Porter <mporter@ti.com>
Acked-by: Chris Ball <cjb@laptop.org> # davinci_mmc.c
Acked-by: Mark Brown <broonie@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
[nsekhar@ti.com: dropped davinci sffsdr changes]
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
2013-06-18 10:52:03 +05:30
Renamed from arch/arm/mach-davinci/dma.c (Browse further)
