Commit graph

21 commits

Author SHA1 Message Date
Robert Jarzmik
88a0513cf6 dmaengine: pxa: add a default requestor policy
As what former drcmr -1 value meant, add a this as a default to each
channel, ie. that by default no requestor line is used.

This is specifically used for network drivers smc91x and smc911x, and
needed for their port to slave maps.

Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Vinod Koul <vkoul@kernel.org>
2018-06-18 21:29:23 +02:00
Robert Jarzmik
420c0117db dmaengine: pxa: use a dma slave map
In order to remove the specific knowledge of the dma mapping from PXA
drivers, add a default slave map for pxa architectures.

This won't impact MMP architecture, but is aimed only at all PXA boards.

This is the first step, and once all drivers are converted,
pxad_filter_fn() will be made static, and the DMA resources removed from
device.c.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Vinod Koul <vkoul@kernel.org>
2018-06-18 21:28:44 +02:00
Robert Jarzmik
556195f492 Revert "dmaengine: pxa_dma: add support for legacy transition"
This reverts commit c91134d919.

The conversion of the pxa architecture is now finished for all
drivers, so this functions has fullfilled its purpose and can
now be removed.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-10-18 20:14:32 +05:30
Robert Jarzmik
06777c4ec7 dmaengine: pxa_dma: fix debug message
In a very tight timeframe, the debug message in the transfer completion
handler can be misleading, as the completion test report can change just
after the message, and the code flow cannot be deduced from the debug
message.

This is just a cleanup to make debugging easier.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-08-19 16:17:26 +05:30
Robert Jarzmik
76507fdfc9 dmaengine: pxa_dma: fix hotchain corner case
In the case where a descriptor is chained on a running channel, and as
explained in the comment in the code 10 lines above, the success of the
chaining is ensured either if :
 - the DMA is still running
 - or if the chained transfer is completed

Unfortunately the transfer completness test was done on the descriptor
to which the transfer was chained, and not the transfer being chained at
the end, ie. hot-chained.

This corner case is extremely hard to trigger, as usually the DMA chain
is still running, and the first case takes care of returning success of
the hot-chaining. It was seen by hot-chaining several "small transfers"
to a running "big transfer", not in a real-life usecase but by testing
the robustness of the driver.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-08-19 12:01:59 +05:30
Robert Jarzmik
7d60466325 dmaengine: pxa_dma: implement device_synchronize
Implement the function which wait until a dma channel is stopped to have
a synchronization point.

This also protects the pxad_remove() from races, such as spurious
interrupts while removing the driver, because :
 - as long as there is one dma channel requested, ie. dma_chan_get() but
   no dma_chan_put(), the try_module_get() of dma_chan_get() prevents
   the remove() routine from running
 - when the last channel is released, ie. the last dma_chan_put() is
   called, if there is a running DMA, pxad_synchronize() is called
 - pxad_synchronize() waits for the channel to stop, which in turn
   ensures on pxa architecture that the interrupt cannot be fired anymore

Reported-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-07-23 16:07:29 +05:30
Vinod Koul
376ab15fe2 dmaengine: pxa_dma: remove owner assignment
debugfs file operations owner is set by core, so remove

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
2016-07-23 16:07:26 +05:30
Eric Engestrom
4e0def887d dmaengine: pxa_dma: remove duplicate const qualifier
Signed-off-by: Eric Engestrom <eric.engestrom@imgtec.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-04-26 21:59:46 +05:30
Robert Jarzmik
e093bf60ca dmaengine: pxa: handle bus errors
In the current state, upon bus error the driver will spin endlessly,
relaunching the last tx, which will fail again and again :
 - a bus error happens
 - pxad_chan_handler() is called
 - as PXA_DCSR_STOPSTATE is true, the last non-terminated transaction is
   lauched, which is the one triggering the bus error, as it didn't
   terminate
 - moreover, the STOP interrupt fires a new, as the STOPIRQEN is still
   active

Break this logic by stopping the automatic relaunch of a dma channel
upon a bus error, even if there are still pending issued requests on it.

As dma_cookie_status() seems unable to return DMA_ERROR in its current
form, ie. there seems no way to mark a DMA_ERROR on a per-async-tx
basis, it is chosen in this patch to remember on the channel which
transaction failed, and report it in pxad_tx_status().

It's a bit misleading because if T1, T2, T3 and T4 were queued, and T1
was completed while T2 causes a bus error, the status of T3 and T4 will
be reported as DMA_IN_PROGRESS, while the channel is actually stopped.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-04-26 09:03:57 +05:30
Linus Torvalds
33b3d2e88c ARM: SoC platform updates for v4.6
Newly added support for additional SoCs:
 
 - Axis Artpec-6 SoC family
 - Allwinner A83T SoC
 - Mediatek MT7623
 - NXP i.MX6QP SoC
 - ST Microelectronics stm32f469 microcontroller
 
 New features:
 - SMP support for Mediatek mt2701
 - Big-endian support for NXP i.MX
 - DaVinci now uses the new DMA engine dma_slave_map
 - OMAP now uses the new DMA engine dma_slave_map
 - earlyprintk support for palmchip uart on mach-tango
 - delay timer support for orion
 
 Other:
 - Exynos PMU driver moved out to drivers/soc/
 - Various smaller updates for Renesas, Xilinx, PXA, AT91, OMAP, uniphier
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Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC platform updates from Arnd Bergmann:
 "Newly added support for additional SoCs:
   - Axis Artpec-6 SoC family
   - Allwinner A83T SoC
   - Mediatek MT7623
   - NXP i.MX6QP SoC
   - ST Microelectronics stm32f469 microcontroller

  New features:
   - SMP support for Mediatek mt2701
   - Big-endian support for NXP i.MX
   - DaVinci now uses the new DMA engine dma_slave_map
   - OMAP now uses the new DMA engine dma_slave_map
   - earlyprintk support for palmchip uart on mach-tango
   - delay timer support for orion

  Other:
   - Exynos PMU driver moved out to drivers/soc/
   - Various smaller updates for Renesas, Xilinx, PXA, AT91, OMAP,
     uniphier"

* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (83 commits)
  ARM: uniphier: rework SMP code to support new System Bus binding
  ARM: uniphier: add missing of_node_put()
  ARM: at91: avoid defining CONFIG_* symbols in source code
  ARM: DRA7: hwmod: Add data for eDMA tpcc, tptc0, tptc1
  ARM: imx: Make reset_control_ops const
  ARM: imx: Do L2 errata only if the L2 cache isn't enabled
  ARM: imx: select ARM_CPU_SUSPEND only for imx6
  dmaengine: pxa_dma: fix the maximum requestor line
  ARM: alpine: select the Alpine MSI controller driver
  ARM: pxa: add the number of DMA requestor lines
  dmaengine: mmp-pdma: add number of requestors
  dma: mmp_pdma: Add the #dma-requests DT property documentation
  ARM: OMAP2+: Add rtc hwmod configuration for ti81xx
  ARM: s3c24xx: Avoid warning for inb/outb
  ARM: zynq: Move early printk virtual address to vmalloc area
  ARM: DRA7: hwmod: Add custom reset handler for PCIeSS
  ARM: SAMSUNG: Remove unused register offset definition
  ARM: EXYNOS: Cleanup header files inclusion
  drivers: soc: samsung: Enable COMPILE_TEST
  MAINTAINERS: Add maintainers entry for drivers/soc/samsung
  ...
2016-03-20 14:57:08 -07:00
Robert Jarzmik
f16921275c dmaengine: pxa_dma: fix cyclic transfers
While testing audio with pxa2xx-ac97, underrun were happening while the
user application was correctly feeding the music. Debug proved that the
cyclic transfer is not cyclic, ie. the last descriptor did not loop on
the first.

Another issue is that the descriptor length was always set to 8192,
because of an trivial operator issue.

This was tested on a pxa27x platform.

Fixes: a57e16cf03 ("dmaengine: pxa: add pxa dmaengine driver")
Reported-by: Vasily Khoruzhick <anarsoul@gmail.com>
Tested-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-03-03 21:06:45 +05:30
Robert Jarzmik
6bab1c6afd dmaengine: pxa_dma: fix the maximum requestor line
The current number of requestor lines is limited to 31. This was an
error of a previous commit, as this number is platform dependent, and is
actually :
 - for pxa25x: 40 requestor lines
 - for pxa27x: 75 requestor lines
 - for pxa3xx: 100 requestor lines

The previous testing did not reveal the faulty constant as on pxa[23]xx
platforms, only camera, MSL and USB are above requestor 32, and in these
only the camera has a driver using dma.

Fixes: e87ffbdf06 ("dmaengine: pxa_dma: fix the no-requestor case")
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Vinod Koul <vinod.koul@intel.com>
2016-02-26 22:57:45 +01:00
Robert Jarzmik
d3651b8e5c dmaengine: pxa_dma: declare transfer are reusable
As this driver provides a mechanism to reuse transfers, declare it in
its probe function.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-11-16 08:32:16 +05:30
Robert Jarzmik
7b09a1bba4 dmaengine: pxa_dma: fix residue corner case
A very tiny temporal window exists in the residue calculation where :
 - upon entering residue calculation, the transfer is ongoing
 - when reading the current transfer pointer, it just changed to
   the "finisher/linker" descriptor

In this case, the residue returned is the whole transfer length instead
of 0. Fix it.

This appears almost in one extreme case, where the driver is used
by older clients which inquire for residue in interrupt context, such
as the smsc91x ethernet driver, in a tight loop :
  interrupt_handler()
    dmaengine_submit()
    do {
      dmaengine_tx_status()
    } while (residue > 0 || status != DMA_ERROR)

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-01 07:44:31 +05:30
Robert Jarzmik
e87ffbdf06 dmaengine: pxa_dma: fix the no-requestor case
A very small number of devices don't use the flow control offered by
requestor lines. In these specific cases, the pxa dma driver should be
aware of that and not try to use a requestor line.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-10-01 07:44:25 +05:30
Robert Jarzmik
aebf5a67db dmaengine: pxa_dma: fix initial list move
Since the commit to have an allocated list of virtual descriptors was
reverted, the pxa_dma driver is broken, as it assumes the descriptor is
placed on the allocated list upon allocation.

Fix the issue in pxa_dma by making an allocated virtual descriptor a
singleton.

Fixes: 8c8fe97b2b ("Revert "dmaengine: virt-dma: don't always free descriptor upon completion"")
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-09-25 07:21:01 +05:30
Robert Jarzmik
4a736d156d dmaengine: pxa_dma: fix debug information
This fixes the following error:
drivers/dma/pxa_dma.c: In function ‘dbg_show_requester_chan’:
drivers/dma/pxa_dma.c:192:2: error: void value not ignored as it ought to be
  pos += seq_printf(s, "DMA channel %d requester :\n", phy->idx);
  ^
drivers/dma/pxa_dma.c:197:8: error: void value not ignored as it ought to be
        !!(drcmr & DRCMR_MAPVLD));
        ^
scripts/Makefile.build:258: recipe for target 'drivers/dma/pxa_dma.o' failed

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-08-18 22:10:09 +05:30
Robert Jarzmik
0e95fb9ceb dmaengine: pxa_dma: don't use config direction parameter
Don't use the direction passed in the configuration, and rely on each
transfer's direction to prepare the transfers. This will enable
future removal of direction parameter from dma_slave_config.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-08-17 14:52:09 +05:30
Robert Jarzmik
c91134d919 dmaengine: pxa_dma: add support for legacy transition
In order to achieve smooth transition of pxa drivers from old legacy dma
handling to new dmaengine, introduce a function to "hide" dma physical
channels from dmaengine.

This is temporary situation where pxa dma will be handled in 2 places :
 - arch/arm/plat-pxa/dma.c
 - drivers/dma/pxa_dma.c

The resources, ie. dma channels, will be controlled by pxa_dma. The
legacy code will request or release a channel with
pxad_toggle_reserved_channel().

This is not very pretty, but it ensures both legacy and dmaengine
consumers can live in the same kernel until the conversion is done.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-05-29 14:42:48 +05:30
Robert Jarzmik
c01d1b5159 dmaengine: pxa_dma: add debug information
Reuse the debugging features which were available in pxa architecture.
This is a copy of the code from arch/arm/plat-pxa/dma, which is doomed
to disappear once the conversion is completed towards dmaengine.

This is a transfer of the commit "[ARM] pxa/dma: add debugfs
entries" (d294948c2c).

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-05-26 09:18:29 +05:30
Robert Jarzmik
a57e16cf03 dmaengine: pxa: add pxa dmaengine driver
This is a new driver for pxa SoCs, which is also compatible with the former
mmp_pdma.

The rationale behind a new driver (as opposed to incremental patching) was :

 - the new driver relies on virt-dma, which obsoletes all the internal
   structures of mmp_pdma (sw_desc, hw_desc, ...), and by consequence all the
   functions

 - mmp_pdma allocates dma coherent descriptors containing not only hardware
   descriptors but linked list information
   The new driver only puts the dma hardware descriptors (ie. 4 u32) into the
   dma pool allocated memory. This changes completely the way descriptors are
   handled

 - the architecture behind the interrupt/tasklet management was rewritten to be
   more conforming to virt-dma

 - the buffers alignment is handled differently
   The former driver assumed that the DMA channel stopped between each
   descriptor. The new one chains descriptors to let the channel running. This
   is a necessary guarantee for real-time high bandwidth usecases such as video
   capture on "old" architectures such as pxa.

 - hot chaining / cold chaining / no chaining
   Whenever possible, submitting a descriptor "hot chains" it to a running
   channel. There is still no guarantee that the descriptor will be issued, as
   the channel might be stopped just before the descriptor is submitted. Yet
   this allows to submit several video buffers, and resubmit a buffer while
   another is under handling.
   As before, dma_async_issue_pending() is the only guarantee to have all the
   buffers issued.
   When an alignment issue is detected (ie. one address in a descriptor is not
   a multiple of 8), if the already running channel is in "aligned mode", the
   channel will stop, and restarted in "misaligned mode" to finished the issued
   list.

 - descriptors reusing
   A submitted, issued and completed descriptor can be reused, ie resubmitted if
   it was prepared with the proper flag (DMA_PREP_ACK).  Only a channel
   resources release will in this case release that buffer.
   This allows a rolling ring of buffers to be reused, where there are several
   thousands of hardware descriptors used (video buffer for example).

Additionally, a set of more casual features is introduced :
 - debugging traces
 - lockless way to know if a descriptor is terminated or not

The driver was tested on zylonite board (pxa3xx) and mioa701 (pxa27x),
with dmatest, pxa_camera and pxamci.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-05-26 09:18:29 +05:30