linux-toradex.git/drivers/dma/at_xdmac.c, branch v5.0

dmaengine: at_xdmac: Fix wrongfull report of a channel as in use

2019-02-02T10:25:26+00:00

atchan->status variable is used to store two different information:
 - pass channel interrupts status from interrupt handler to tasklet;
 - channel information like whether it is cyclic or paused;

This causes a bug when device_terminate_all() is called,
(AT_XDMAC_CHAN_IS_CYCLIC cleared on atchan->status) and then a late End
of Block interrupt arrives (AT_XDMAC_CIS_BIS), which sets bit 0 of
atchan->status. Bit 0 is also used for AT_XDMAC_CHAN_IS_CYCLIC, so when
a new descriptor for a cyclic transfer is created, the driver reports
the channel as in use:

if (test_and_set_bit(AT_XDMAC_CHAN_IS_CYCLIC, &atchan->status)) {
	dev_err(chan2dev(chan), "channel currently used\n");
	return NULL;
}

This patch fixes the bug by adding a different struct member to keep
the interrupts status separated from the channel status bits.

Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Codrin Ciubotariu 
Acked-by: Ludovic Desroches 
Signed-off-by: Vinod Koul

dmaengine: at_xdmac: move spin_lock_bh to spin_lock in tasklet

2018-09-03T10:54:05+00:00

as you are already in a tasklet, it is unnecessary to call spin_lock_bh.

Signed-off-by: Barry Song <21cnbao@gmail.com>
Acked-by: Ludovic Desroches 
Signed-off-by: Vinod Koul

dmaengine: at_xdmac: simplify getting .drvdata

2018-04-22T16:06:10+00:00

We should get drvdata from struct device directly. Going via
platform_device is an unneeded step back and forth.

Signed-off-by: Wolfram Sang 
Signed-off-by: Vinod Koul

dmaengine: at_xdmac: fix rare residue corruption

2018-03-27T12:03:44+00:00

Despite the efforts made to correctly read the NDA and CUBC registers,
the order in which the registers are read could sometimes lead to an
inconsistent state.

Re-using the timeline from the comments, this following timing of
registers reads could lead to reading NDA with value "@desc2" and
CUBC with value "MAX desc1":

 INITD --------                    ------------
              |____________________|
       _______________________  _______________
 NDA       @desc2             \/   @desc3
       _______________________/\_______________
       __________  ___________  _______________
 CUBC       0    \/ MAX desc1 \/  MAX desc2
       __________/\___________/\_______________
        |  |          |  |
Events:(1)(2)        (3)(4)

(1) check_nda = @desc2
(2) initd = 1
(3) cur_ubc = MAX desc1
(4) cur_nda = @desc2

This is allowed by the condition ((check_nda == cur_nda) && initd),
despite cur_ubc and cur_nda being in the precise state we don't want.

This error leads to incorrect residue computation.

Fix it by inversing the order in which CUBC and INITD are read. This
makes sure that NDA and CUBC are always read together either _before_
INITD goes to 0 or _after_ it is back at 1.
The case where NDA is read before INITD is at 0 and CUBC is read after
INITD is back at 1 will be rejected by check_nda and cur_nda being
different.

Fixes: 53398f488821 ("dmaengine: at_xdmac: fix residue corruption")
Cc: stable@vger.kernel.org
Signed-off-by: Maxime Jayat 
Acked-by: Ludovic Desroches 
Signed-off-by: Vinod Koul

dmaengine: at_xdmac: Handle return value of clk_prepare_enable.

2017-08-21T16:50:44+00:00

clk_prepare_enable() can fail here and we must check its return value.

Signed-off-by: Arvind Yadav 
Acked-by: Ludovic Desroches 
Signed-off-by: Vinod Koul

dmaengine: at_xdmac: Fix compilation warning.

2017-08-21T16:50:43+00:00

Replace '%d' by '%zu' to fix the compilation warning:-
   "format ‘%d’ expects argument of type ‘int’,but argument has type ‘size_t’ [-Wformat=]"

Signed-off-by: Arvind Yadav 
Acked-by: Ludovic Desroches 
Signed-off-by: Vinod Koul

dmaengine: at_xdmac: don't restore unsaved status

2016-12-06T05:15:48+00:00

save_gs is supposed to save the channel status in order to be restored at
resume time but it is never updated and is always 0. Anyway, the channel
status is updated in the per channel loop later in the resume function.

Signed-off-by: Alexandre Belloni 
Acked-by: Nicolas Ferre 
Acked-by: Ludovic Desroches 
Signed-off-by: Vinod Koul

dmaengine: at_xdmac: Use dma_pool_zalloc

2016-11-30T03:20:46+00:00

We should use dma_pool_zalloc instead of dma_pool_alloc/memset.

Signed-off-by: Souptick joarder 
Signed-off-by: Vinod Koul

Merge tag 'dmaengine-4.9-rc1' of git://git.infradead.org/users/vkoul/slave-dma

2016-10-07T00:13:54+00:00

Pull dmaengine updates from Vinod Koul:
 "This is bit large pile of code which bring in some nice additions:

   - Error reporting: we have added a new mechanism for users of
     dmaenegine to register a callback_result which tells them the
     result of the dma transaction. Right now only one user (ntb) is
     using it.

   - As we discussed on KS mailing list and pointed out NO_IRQ has no
     place in kernel, this also remove NO_IRQ from dmaengine subsystem
     (both arm and ppc users)

   - Support for IOMMU slave transfers and its implementation for arm.

   - To get better build coverage, enable COMPILE_TEST for bunch of
     driver, and fix the warning and sparse complaints on these.

   - Apart from above, usual updates spread across drivers"

* tag 'dmaengine-4.9-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (169 commits)
  async_pq_val: fix DMA memory leak
  dmaengine: virt-dma: move function declarations
  dmaengine: omap-dma: Enable burst and data pack for SG
  DT: dmaengine: rcar-dmac: document R8A7743/5 support
  dmaengine: fsldma: Unmap region obtained by of_iomap
  dmaengine: jz4780: fix resource leaks on error exit return
  dma-debug: fix ia64 build, use PHYS_PFN
  dmaengine: coh901318: fix integer overflow when shifting more than 32 places
  dmaengine: edma: avoid uninitialized variable use
  dma-mapping: fix m32r build warning
  dma-mapping: fix ia64 build, use PHYS_PFN
  dmaengine: ti-dma-crossbar: enable COMPILE_TEST
  dmaengine: omap-dma: enable COMPILE_TEST
  dmaengine: edma: enable COMPILE_TEST
  dmaengine: ti-dma-crossbar: Fix of_device_id data parameter usage
  dmaengine: ti-dma-crossbar: Correct type for of_find_property() third parameter
  dmaengine/ARM: omap-dma: Fix the DMAengine compile test on non OMAP configs
  dmaengine: edma: Rename set_bits and remove unused clear_bits helper
  dmaengine: edma: Use correct type for of_find_property() third parameter
  dmaengine: edma: Fix of_device_id data parameter usage (legacy vs TPCC)
  ...

dmaengine: at_xdmac: fix to pass correct device identity to free_irq()

2016-08-22T06:22:25+00:00

free_irq() expects the same device identity that was passed to
corresponding request_irq(), otherwise the IRQ is not freed.

Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Wei Yongjun 
Acked-by: Ludovic Desroches 
Signed-off-by: Vinod Koul