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The pl330 DMA driver is broken in regard to handling a terminate all request while it is processing the list of completed descriptors. This is most visible when calling dmaengine_terminate_all() from within the descriptors callback for cyclic transfers. In this case the TERMINATE_ALL transfer will clear the work_list and stop the transfer. But after all callbacks for all completed descriptors have been handled the descriptors will be re-enqueued into the (now empty) work_list. So the next time dma_async_issue_pending() is called for the channel these descriptors will be transferred again which will cause data corruption. Similar issues can occur if dmaengine_terminate_all() is not called from within the descriptor callback but runs on a different CPU at the same time as the completed descriptor list is processed. This patch introduces a new per channel list which will hold the completed descriptors. While processing the list the channel's lock will be held to avoid racing against dmaengine_terminate_all(). The lock will be released when calling the descriptors callback though. Since the list of completed descriptors might be modified (e.g. by calling dmaengine_terminate_all() from the callback) we can not use the normal list iterator macros. Instead we'll need to check for each loop iteration again if there are still items in the list. The drivers TERMINATE_ALL implementation is updated to move descriptors from both the work_list as well the new completed_list back to the descriptor pool. This makes sure that none of the descripts finds its way back into the work list and also that we do not call any futher complete callbacks after dmaengine_terminate_all() has been called. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com> |
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.. | ||
bestcomm | ||
dw | ||
ioat | ||
ipu | ||
ppc4xx | ||
sh | ||
acpi-dma.c | ||
amba-pl08x.c | ||
at_hdmac_regs.h | ||
at_hdmac.c | ||
coh901318_lli.c | ||
coh901318.c | ||
coh901318.h | ||
dma-jz4740.c | ||
dmaengine.c | ||
dmaengine.h | ||
dmatest.c | ||
edma.c | ||
ep93xx_dma.c | ||
fsldma.c | ||
fsldma.h | ||
imx-dma.c | ||
imx-sdma.c | ||
intel_mid_dma_regs.h | ||
intel_mid_dma.c | ||
iop-adma.c | ||
iovlock.c | ||
k3dma.c | ||
Kconfig | ||
Makefile | ||
mmp_pdma.c | ||
mmp_tdma.c | ||
mpc512x_dma.c | ||
mv_xor.c | ||
mv_xor.h | ||
mxs-dma.c | ||
of-dma.c | ||
omap-dma.c | ||
pch_dma.c | ||
pl330.c | ||
sa11x0-dma.c | ||
sirf-dma.c | ||
ste_dma40_ll.c | ||
ste_dma40_ll.h | ||
ste_dma40.c | ||
tegra20-apb-dma.c | ||
timb_dma.c | ||
TODO | ||
txx9dmac.c | ||
txx9dmac.h | ||
virt-dma.c | ||
virt-dma.h |