linux/drivers/dma
Ben Dooks e486df3930 dmaengine: tegra: avoid overflow of byte tracking
The dma_desc->bytes_transferred counter tracks the number of bytes
moved by the DMA channel. This is then used to calculate the information
passed back in the in the tegra_dma_tx_status callback, which is usually
fine.

When the DMA channel is configured as continous, then the bytes_transferred
counter will increase over time and eventually overflow to become negative
so the residue count will become invalid and the ALSA sound-dma code will
report invalid hardware pointer values to the application. This results in
some users becoming confused about the playout position and putting audio
data in the wrong place.

To fix this issue, always ensure the bytes_transferred field is modulo the
size of the request. We only do this for the case of the cyclic transfer
done ISR as anyone attempting to move 2GiB of DMA data in one transfer
is unlikely.

Note, we don't fix the issue that we should /never/ transfer a negative
number of bytes so we could make those fields unsigned.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2019-01-07 09:52:41 +05:30
..
bestcomm treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
dw dmaengine-4.21-rc1 2019-01-01 15:45:48 -08:00
dw-axi-dmac dmaengine: dw-axi-dmac: use dmaenginem_async_device_register to simplify the code 2018-08-29 21:43:17 +05:30
hsu dmaengine: hsu: remove dma_slave_config direction usage 2018-10-07 19:25:09 +05:30
ioat pci-v4.20-changes 2018-10-25 06:50:48 -07:00
ipu treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
mediatek dmaengine: mediatek: Add MediaTek Command-Queue DMA controller for MT6765 SoC 2018-11-11 15:15:18 +05:30
ppc4xx dmaengine: ppc4xx: fix off-by-one build failure 2018-10-16 20:08:30 +05:30
qcom dmaengine: qcom_hidma: convert to DEFINE_SHOW_ATTRIBUTE 2018-12-17 11:49:41 +05:30
sh IOMMU Updates for Linux v4.21 2019-01-01 15:55:29 -08:00
ti dmaengine: cppi41: delete channel from pending list when stop channel 2018-12-05 14:01:59 +05:30
xilinx Merge branch 'topic/xilinx' into for-linus 2018-12-31 19:32:32 +05:30
acpi-dma.c
altera-msgdma.c dmaengine: altera: Use IRQ-safe spinlock calls in the error paths as well 2017-10-20 11:51:10 +05:30
amba-pl08x.c dmaengine: amba-pl08x: convert to DEFINE_SHOW_ATTRIBUTE 2018-12-17 11:49:41 +05:30
at_hdmac_regs.h dmaengine: at_hdmac: Remove unnecessary 0x prefixes before %pad 2017-11-08 10:47:04 +05:30
at_hdmac.c dmaengine: at_hdmac: fix module unloading 2018-11-29 19:49:41 +05:30
at_xdmac.c dmaengine: at_xdmac: move spin_lock_bh to spin_lock in tasklet 2018-09-03 16:24:05 +05:30
bcm2835-dma.c dmaengine: bcm2835: Switch to SPDX identifier 2018-11-11 14:42:19 +05:30
bcm-sba-raid.c treewide: Use struct_size() for devm_kmalloc() and friends 2018-06-06 11:15:43 -07:00
coh901318_lli.c
coh901318.c dmaengine: coh901318: Remove unused variable 2018-11-26 13:35:52 +05:30
coh901318.h
dma-axi-dmac.c dmaengine: axi-dmac: Request IRQ with IRQF_SHARED 2018-05-02 10:06:42 +05:30
dma-jz4740.c dmaengine: jz4740: remove dma_slave_config direction usage 2018-10-07 19:20:14 +05:30
dma-jz4780.c Merge branch 'topic/jz' into for-linus 2018-10-24 09:16:04 +01:00
dmaengine.c Merge branch 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax 2018-08-26 11:48:42 -07:00
dmaengine.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dmatest.c dmaengine: dmatest: Add transfer_size parameter 2018-12-17 11:45:11 +05:30
ep93xx_dma.c dmaengine: ep93xx: fix some typo 2018-11-11 14:56:49 +05:30
fsl_raid.c
fsl_raid.h
fsl-edma-common.c dmaengine: fsl-edma: remove dma_slave_config direction usage 2018-10-09 14:29:58 +05:30
fsl-edma-common.h dmaengine: fsl-edma: remove dma_slave_config direction usage 2018-10-09 14:29:58 +05:30
fsl-edma.c dmaengine: fsl-edma: add edma version and configurable registers 2018-09-11 12:06:39 +05:30
fsldma.c dmaengine: fsldma: move spin_lock_bh to spin_lock in tasklet 2018-09-03 16:23:00 +05:30
fsldma.h
idma64.c Merge branch 'topic/intel' into for-linus 2018-10-24 09:15:59 +01:00
idma64.h
img-mdc-dma.c dmaengine: img-mdc-dma: Use vchan_terminate_vdesc() instead of desc_free 2017-12-04 22:33:51 +05:30
imx-dma.c dmaengine: imx-dma: remove dma_slave_config direction usage 2018-10-07 19:25:10 +05:30
imx-sdma.c dmaengine-4.21-rc1 2019-01-01 15:45:48 -08:00
iop-adma.c
k3dma.c dmaengine: k3dma: remove dma_slave_config direction usage 2018-10-07 19:25:10 +05:30
Kconfig dmaengine: uniphier-mdmac: add UniPhier MIO DMAC driver 2018-11-24 19:42:59 +05:30
lpc18xx-dmamux.c
Makefile dmaengine: uniphier-mdmac: add UniPhier MIO DMAC driver 2018-11-24 19:42:59 +05:30
mcf-edma.c dmaengine: mcf-edma: avoid warning for wrong pointer cast 2018-09-18 12:15:45 -07:00
mic_x100_dma.c dmaengine: mic_x100_dma: convert to DEFINE_SHOW_ATTRIBUTE 2018-12-17 11:49:41 +05:30
mic_x100_dma.h
mmp_pdma.c dmaengine: mmp_pdma: remove dma_slave_config direction usage 2018-11-05 10:32:46 +05:30
mmp_tdma.c Merge branch 'topic/dmam' into for-linus 2018-10-24 09:15:43 +01:00
moxart-dma.c treewide: Use struct_size() for kmalloc()-family 2018-06-06 11:15:43 -07:00
mpc512x_dma.c
mv_xor_v2.c dmaengine: mv_xor_v2: use {lower,upper}_32_bits to configure HW descriptor address 2018-07-25 17:53:22 +05:30
mv_xor.c dmaengine: mv_xor: move spin_lock_bh to spin_lock in tasklet 2018-09-03 16:23:31 +05:30
mv_xor.h
mxs-dma.c dmaengine: mxs-dma: use dmaenginem_async_device_register to simplify the code 2018-08-29 21:43:18 +05:30
nbpfaxi.c Merge branch 'topic/renesas' into for-linus 2018-10-24 09:16:22 +01:00
of-dma.c
owl-dma.c dmaengine: owl: Fix warnings generated during build 2018-10-15 22:39:16 +05:30
pch_dma.c dmaengine: pch_dma: Replace PCI pool old API 2017-10-31 17:01:06 +05:30
pl330.c dmaengine: pl330: remove dma_slave_config direction usage 2018-11-24 20:22:21 +05:30
pxa_dma.c dmaengine-4.21-rc1 2019-01-01 15:45:48 -08:00
s3c24xx-dma.c headers: separate linux/mod_devicetable.h from linux/platform_device.h 2018-07-07 17:52:26 +02:00
sa11x0-dma.c dmaengine: sa11x0: unexport sa11x0_dma_filter_fn and clean up 2018-11-11 14:54:08 +05:30
sirf-dma.c
sprd-dma.c dmaengine: sprd: Add me as one of the module authors 2018-12-05 14:27:12 +05:30
st_fdma.c dmaengine: st_fdma: use dmaenginem_async_device_register to simplify the code 2018-08-29 21:43:17 +05:30
st_fdma.h
ste_dma40_ll.c
ste_dma40_ll.h
ste_dma40.c dmaengine: ste_dma40: remove dma_slave_config direction usage 2018-11-24 20:22:21 +05:30
stm32-dma.c dmaengine: stm32-dma: check whether length is aligned on FIFO threshold 2018-10-02 20:32:15 +05:30
stm32-dmamux.c dmaengine: stm32-dmamux: fix a potential buffer overflow 2018-03-22 10:51:35 +05:30
stm32-mdma.c dmaengine: stm32-mdma: use dmaenginem_async_device_register to simplify the code 2018-08-29 21:43:17 +05:30
sun4i-dma.c
sun6i-dma.c dmaengine: sun6i: Retrieve channel count/max request from devicetree 2017-10-23 11:44:03 +05:30
tegra20-apb-dma.c dmaengine: tegra: avoid overflow of byte tracking 2019-01-07 09:52:41 +05:30
tegra210-adma.c
timb_dma.c dmaengine: timb_dma: Use proper enum in td_prep_slave_sg 2018-10-02 20:11:09 +05:30
TODO
txx9dmac.c dmaengine: txx9dmac: simplify getting .drvdata 2018-04-22 21:38:06 +05:30
txx9dmac.h
uniphier-mdmac.c dmaengine: uniphier-mdmac: add UniPhier MIO DMAC driver 2018-11-24 19:42:59 +05:30
virt-dma.c dmaengine: virt-dma: Add helper to free/reuse a descriptor 2017-12-04 22:33:51 +05:30
virt-dma.h dmaengine: virt-dma: Support for race free transfer termination 2017-12-04 22:33:51 +05:30
xgene-dma.c
zx_dma.c treewide: devm_kzalloc() -> devm_kcalloc() 2018-06-12 16:19:22 -07:00