OpenCloudOS-Kernel/drivers/dma/sh
Geert Uytterhoeven 78efb76ab4 dmaengine: rcar-dmac: Reject zero-length slave DMA requests
While the .device_prep_slave_sg() callback rejects empty scatterlists,
it still accepts single-entry scatterlists with a zero-length segment.
These may happen if a driver calls dmaengine_prep_slave_single() with a
zero len parameter.  The corresponding DMA request will never complete,
leading to messages like:

    rcar-dmac e7300000.dma-controller: Channel Address Error happen

and DMA timeouts.

Although requesting a zero-length DMA request is a driver bug, rejecting
it early eases debugging.  Note that the .device_prep_dma_memcpy()
callback already rejects requests to copy zero bytes.

Reported-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Analyzed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2019-06-25 10:08:22 +05:30
..
Kconfig dmaengine: sudmac: remove unused driver 2019-05-21 09:52:50 +05:30
Makefile dmaengine: sudmac: remove unused driver 2019-05-21 09:52:50 +05:30
rcar-dmac.c dmaengine: rcar-dmac: Reject zero-length slave DMA requests 2019-06-25 10:08:22 +05:30
shdma-arm.h dmaengine: use SPDX identifier for Renesas drivers 2018-08-29 21:58:49 +05:30
shdma-base.c dmaengine: use SPDX identifier for Renesas drivers 2018-08-29 21:58:49 +05:30
shdma-of.c dmaengine: use SPDX identifier for Renesas drivers 2018-08-29 21:58:49 +05:30
shdma.h dmaengine: sh: Remove R-Mobile APE6 support 2018-12-05 13:01:54 +05:30
shdmac.c dmaengine: sh: Remove R-Mobile APE6 support 2018-12-05 13:01:54 +05:30
usb-dmac.c dmaengine: sh: usb-dmac: Use [] to denote a flexible array member 2019-06-25 09:57:42 +05:30