kernel.git/drivers/dma/at_xdmac.c, branch linux-5.18.y

dmaengine: at_xdma: handle errors of at_xdmac_alloc_desc() correctly

2022-07-12T14:42:26Z

commit 3770d92bd5237d686e49da7b2fb86f53ee6ed259 upstream. It seems that it is valid to have less than the requested number of descriptors. But what is not valid and leads to subsequent errors is to have zero descriptors. In that case, abort the probing. Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver") Signed-off-by: Michael Walle Link: https://lore.kernel.org/r/20220526135111.1470926-1-michael@walle.cc Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

dma: at_xdmac: fix a missing check on list iterator

2022-04-11T13:33:29Z

The bug is here: __func__, desc, &desc->tx_dma_desc.phys, ret, cookie, residue); The list iterator 'desc' will point to a bogus position containing HEAD if the list is empty or no element is found. To avoid dev_dbg() prints a invalid address, use a new variable 'iter' as the list iterator, while use the origin variable 'desc' as a dedicated pointer to point to the found element. Cc: stable@vger.kernel.org Fixes: 82e2424635f4c ("dmaengine: xdmac: fix print warning on dma_addr_t variable") Signed-off-by: Xiaomeng Tong Link: https://lore.kernel.org/r/20220327061154.4867-1-xiam0nd.tong@gmail.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: Fix missing unlock in at_xdmac_tasklet()

2022-02-15T05:26:04Z

Add the missing unlock before return from at_xdmac_tasklet(). Fixes: e77e561925df ("dmaengine: at_xdmac: Fix race over irq_status") Reported-by: Hulk Robot Signed-off-by: Yang Yingliang Reviewed-by: Tudor Ambarus Link: https://lore.kernel.org/r/20220107024047.1051915-1-yangyingliang@huawei.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: Fix race over irq_status

2022-01-05T10:20:04Z

Tasklets run with interrupts enabled, so we need to protect atchan->irq_status with spin_lock_irq() otherwise the tasklet can be interrupted by the IRQ that modifies irq_status. Move the dev_dbg that prints the irq_status in at_xdmac_handle_cyclic() and lower in at_xdmac_tasklet() where the IRQ is disabled. Signed-off-by: Tudor Ambarus Link: https://lore.kernel.org/r/20211215110115.191749-13-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: Remove a level of indentation in at_xdmac_tasklet()

2022-01-05T10:20:04Z

Apart of making the code easier to read, this patch is a prerequisite for a functional change: tasklets run with interrupts enabled, so we need to protect atchan->irq_status with spin_lock_irq() otherwise the tasklet can be interrupted by the IRQ that modifies irq_status. atchan->irq_status will be protected in a further patch. Signed-off-by: Tudor Ambarus Link: https://lore.kernel.org/r/20211215110115.191749-12-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: Fix at_xdmac_lld struct definition

2022-01-05T10:20:04Z

The hardware channel next descriptor view structure contains just fields of 32 bits, while dma_addr_t can be of type u64 or u32 depending on CONFIG_ARCH_DMA_ADDR_T_64BIT. Force u32 to comply with what the hardware expects. Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver") Signed-off-by: Tudor Ambarus Link: https://lore.kernel.org/r/20211215110115.191749-11-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: Fix lld view setting

2022-01-05T10:20:04Z

AT_XDMAC_CNDC_NDVIEW_NDV3 was set even for AT_XDMAC_MBR_UBC_NDV2, because of the wrong bit handling. Fix it. Fixes: ee0fe35c8dcd ("dmaengine: xdmac: Handle descriptor's view 3 registers") Signed-off-by: Tudor Ambarus Link: https://lore.kernel.org/r/20211215110115.191749-10-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: Remove a level of indentation in at_xdmac_advance_work()

2022-01-05T10:20:03Z

It's easier to read code with fewer levels of indentation, remove a level of indentation in at_xdmac_advance_work() if (!foo() & !bar()) { } was replaced by: if (foo() || bar()) return; Signed-off-by: Tudor Ambarus Link: https://lore.kernel.org/r/20211215110115.191749-9-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: Fix concurrency over xfers_list

2022-01-05T10:20:03Z

Since tx_submit can be called from a hard IRQ, xfers_list must be protected with a lock to avoid concurency on the list's elements. Since at_xdmac_handle_cyclic() is called from a tasklet, spin_lock_irq is enough to protect from a hard IRQ. Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver") Signed-off-by: Tudor Ambarus Link: https://lore.kernel.org/r/20211215110115.191749-8-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: Move the free desc to the tail of the desc list

2022-01-05T10:20:03Z

Move the free desc to the tail of the list, so that the sequence of descriptors is more track-able in case of debug. One would know which descriptor should come next and could easier catch concurrency over descriptors for example. virt-dma uses list_splice_tail_init() as well, follow the core driver. Signed-off-by: Tudor Ambarus Link: https://lore.kernel.org/r/20211215110115.191749-7-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul