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4ac31d18e4
linux/drivers/dma
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John Ogness 4ac31d18e4 dmaengine: edma: fix residue race for cyclic 
When retrieving the residue value, the SRC/DST fields of the
active PaRAM are read to determine the current position of
the DMA engine. However, the AM335x Technical Reference Manual
states:

  11.3.3.6 Parameter Set Updates

  After the TR is read from the PaRAM (and is in the process
  of being submitted to the EDMA3TC), the following fields are
  updated as needed: ... SRC DST

This means SRC/DST is incremented even though the DMA transfer
may not have started yet or is in progress. Thus if the reader
of the residue accesses the DMA buffer too quickly, the CPU is
misinformed about the data that has been successfully processed.

The CCSTAT.ACTV register is a boolean that is set if any TR is
being processed by either the EMDA3CC or EDMA3TC. By polling
this register it is possible to ensure that the residue value
returned is valid for immediate processing. However, since the
DMA engine may be active, polling may never hit a moment where
no TR is being processed. To handle this, the SRC/DST is also
polled to see if it changes. And as a last resort, a max loop
count for the busy waiting exists to avoid an infinite loop.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-02-08 08:42:55 +05:30
..
bestcomm dmaengine: constify of_device_id array 2015-03-18 22:13:14 +05:30
dw dmaengine: dw: pci: add ID for WildcatPoint PCH 2016-02-08 08:35:17 +05:30
hsu dmaengine: hsu: speed up residue calculation 2015-12-05 14:00:34 +05:30
ioat dmaengine: IOATDMA: fix timer code that continues to restart channels during idle 2016-01-30 22:29:03 +05:30
ipu genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
ppc4xx dmaengine: Remove FSF mailing addresses 2015-03-16 22:28:15 +05:30
sh dmaengine updates for 4.5-rc1 2016-01-13 10:59:52 -08:00
xilinx dmaengine: xilinx: Fix module autoload for OF platform driver 2015-10-01 07:35:39 +05:30
acpi-dma.c dmaengine: acpi-dma: check for 64-bit MMIO address 2015-12-05 14:00:34 +05:30
amba-pl08x.c dmaengine: pl08x: support dt channel assignment 2015-08-18 22:12:14 +05:30
at_hdmac_regs.h dmaengine: at_hdmac: use %pad format string for dma_addr_t 2015-11-16 09:21:05 +05:30
at_hdmac.c dmaengine: at_hdmac: use %pad format string for dma_addr_t 2015-11-16 09:21:05 +05:30
at_xdmac.c dmaengine fixes for 4.5-rc1 2016-01-20 10:15:21 -08:00
bcm2835-dma.c dmaengine: bcm2835-dma: Convert to use DMA pool 2015-12-05 15:36:32 +05:30
coh901318_lli.c
coh901318.c dmaengine: Add an enum for the dmaengine alignment constraints 2015-08-05 10:53:52 +05:30
coh901318.h
cppi41.c dmaengine: cppi41: add missing bitfields 2015-04-11 21:12:58 +05:30
dma-axi-dmac.c dmaengine: axi_dmac: Add synchronization support 2015-11-16 08:28:52 +05:30
dma-jz4740.c Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2015-04-24 09:49:37 -07:00
dma-jz4780.c dmaengine: jz4780: Kill tasklets before unregistering the device 2015-08-18 22:28:50 +05:30
dmaengine.c Merge branch 'topic/async' into for-linus 2016-01-06 15:17:47 +05:30
dmaengine.h
dmatest.c kernel/params: constify struct kernel_param_ops uses 2015-05-28 11:32:10 +09:30
edma.c dmaengine: edma: fix residue race for cyclic 2016-02-08 08:42:55 +05:30
ep93xx_dma.c dmaengine: ep93xx: Constify platform_device_id 2015-05-04 16:38:55 +05:30
fsl_raid.c dmaengine: fsl_raid: statify fsl_re_chan_probe 2015-04-02 16:11:35 +05:30
fsl_raid.h dmaengine: Driver support for FSL RaidEngine device. 2015-04-02 16:10:27 +05:30
fsl-edma.c dmaengine: fsl-edma: add PM suspend/resume support 2015-12-05 15:52:13 +05:30
fsldma.c dmaengine: fsldma: Fix module autoload for OF platform driver 2015-10-01 07:34:31 +05:30
fsldma.h dmaengine: fsldma: declare slave capabilities for the generic code 2015-01-13 23:58:08 +05:30
idma64.c dmaengine: idma64: use local variable to index descriptor 2015-12-05 13:54:28 +05:30
idma64.h dmaengine: idma64: set maximum allowed segment size for DMA 2015-12-05 13:54:28 +05:30
img-mdc-dma.c dmaengine: mdc: Correct terminate_all handling 2015-12-18 11:12:29 +05:30
imx-dma.c dmaengine: Add an enum for the dmaengine alignment constraints 2015-08-05 10:53:52 +05:30
imx-sdma.c dmaengine: imx-sdma: remove __init annotation on sdma_event_remap 2015-11-16 09:14:25 +05:30
iop-adma.c drivers/dma/iop-adma: Use dma_alloc_writecombine() kernel-style 2015-08-25 09:59:46 +02:00
k3dma.c dmaengine: Add an enum for the dmaengine alignment constraints 2015-08-05 10:53:52 +05:30
Kconfig sound updates for 4.5-rc1 2016-01-17 12:05:31 -08:00
lpc18xx-dmamux.c dmaengine: add driver for lpc18xx dmamux 2015-08-18 22:12:14 +05:30
Makefile dmaengine: Add STM32 DMA driver 2015-11-16 08:56:10 +05:30
mic_x100_dma.c dmaengine: Revert "dmaengine: mic_x100: add missing spin_unlock" 2016-01-06 15:16:36 +05:30
mic_x100_dma.h dmaengine: Add an enum for the dmaengine alignment constraints 2015-08-05 10:53:52 +05:30
mmp_pdma.c dmaengine: Add an enum for the dmaengine alignment constraints 2015-08-05 10:53:52 +05:30
mmp_tdma.c dmaengine: Add an enum for the dmaengine alignment constraints 2015-08-05 10:53:52 +05:30
moxart-dma.c dmaengine: moxart-dma: Fix module autoload for OF platform driver 2015-10-01 07:34:31 +05:30
mpc512x_dma.c dmaengine: mpc512x: Fix module autoload for OF platform driver 2015-10-01 07:34:31 +05:30
mv_xor.c dmaengine: mv_xor: add suspend/resume support 2016-01-06 15:42:27 +05:30
mv_xor.h dmaengine: mv_xor: add suspend/resume support 2016-01-06 15:42:27 +05:30
mxs-dma.c dmaengine: mxs: Constify platform_device_id 2015-05-04 16:38:55 +05:30
nbpfaxi.c dmaengine: nbpfaxi: Constify platform_device_id 2015-05-04 16:38:55 +05:30
of-dma.c dmaengine: of_dma: Support for DMA routers 2015-05-09 17:11:25 +05:30
omap-dma.c Merge branch 'topic/omap' into for-linus 2016-01-06 15:18:19 +05:30
pch_dma.c dmaengine: Remove remaining FSF mailing addresses 2015-07-06 19:18:53 +05:30
pl330.c dmaengine updates for 4.3-rc1 2015-09-04 11:10:18 -07:00
pxa_dma.c dmaengine: pxa_dma: declare transfer are reusable 2015-11-16 08:32:16 +05:30
qcom_bam_dma.c Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2015-04-24 09:49:37 -07:00
s3c24xx-dma.c dmaengine: s3c24xx: Constify platform_device_id 2015-05-04 16:38:55 +05:30
sa11x0-dma.c dmaengine: sa11x0: report slave capabilities to upper layers 2015-04-17 23:24:35 +05:30
sirf-dma.c dmaengine: sirf: Fix module autoload for OF platform driver 2015-10-01 07:34:31 +05:30
ste_dma40_ll.c
ste_dma40_ll.h
ste_dma40.c ste_dma40: Delete an unnecessary variable initialisation in d40_probe() 2015-12-10 09:17:10 +05:30
stm32-dma.c dmaengine: stm32-dma: Fix unchecked deference of chan->desc 2015-12-10 09:45:22 +05:30
sun4i-dma.c dmaengine: sun4i: fix unsafe list iteration 2015-09-30 12:17:22 +05:30
sun6i-dma.c dmaengine: sun6i: Fix module autoload for OF platform driver 2015-10-01 07:35:26 +05:30
tegra20-apb-dma.c dmaengine: tegra-apb: Free interrupts before killing tasklets 2015-12-05 16:13:08 +05:30
ti-dma-crossbar.c dmaengine: ti-dma-crossbar: dra7: Support for reserving DMA event ranges 2015-11-30 15:09:16 +05:30
timb_dma.c dmaengine: Remove remaining FSF mailing addresses 2015-07-06 19:18:53 +05:30
TODO
txx9dmac.c
txx9dmac.h
virt-dma.c dmaengine: virt-dma: don't always free descriptor upon completion 2015-11-16 08:32:16 +05:30
virt-dma.h Merge branch 'topic/async' into for-linus 2016-01-06 15:17:47 +05:30
xgene-dma.c dmaengine: xgene-dma: Fix double IRQ issue by setting IRQ_DISABLE_UNLAZY flag 2016-01-07 11:09:36 +05:30
zx296702_dma.c dmaengine updates for 4.4-rc1 2015-11-10 10:05:17 -08:00