kernel/linux.git/drivers/dma/mediatek, branch v6.19.11

dmaengine: mediatek: uart-apdma: Fix above 4G addressing TX/RX

2026-02-26T23:01:23+00:00

[ Upstream commit 58ab9d7b6651d21e1cff1777529f2d3dd0b4e851 ] The VFF_4G_SUPPORT register is named differently in datasheets, and its name is "VFF_ADDR2"; was this named correctly from the beginning it would've been clearer that there was a mistake in the programming sequence. This register is supposed to hold the high bits to support the DMA addressing above 4G (so, more than 32 bits) and not a bit to "enable" the support for VFF 4G. Fix the name of this register, and also fix its usage by writing the upper 32 bits of the dma_addr_t on it when the SoC supports such feature. Fixes: 9135408c3ace ("dmaengine: mediatek: Add MediaTek UART APDMA support") Signed-off-by: AngeloGioacchino Del Regno Link: https://patch.msgid.link/20251113122229.23998-6-angelogioacchino.delregno@collabora.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

dmaengine: mediatek: Fix a flag reuse error in mtk_cqdma_tx_status()

2025-06-26T22:09:20+00:00

Fixed a flag reuse bug in the mtk_cqdma_tx_status() function. Fixes: 157ae5ffd76a ("dmaengine: mediatek: Fix a possible deadlock error in mtk_cqdma_tx_status()") Cc: stable@vger.kernel.org Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202505270641.MStzJUfU-lkp@intel.com/ Signed-off-by: Qiu-ji Chen Reviewed-by: Eugen Hristev Reviewed-by: AngeloGioacchino Del Regno Link: https://lore.kernel.org/r/20250606090017.5436-1-chenqiuji666@gmail.com Signed-off-by: Vinod Koul

dmaengine: mediatek: drop unused variable

2025-05-15T10:42:13+00:00

Commit 157ae5ffd76a dmaengine: mediatek: Fix a possible deadlock error in mtk_cqdma_tx_status() fixed locks but kept unused varibale leading to warning and build failure (due to warning treated as errors) drivers/dma/mediatek/mtk-cqdma.c: In function 'mtk_cqdma_find_active_desc': drivers/dma/mediatek/mtk-cqdma.c:423:23: error: unused variable 'flags' [-Werror=unused-variable] 423 | unsigned long flags; | ^~~~~ Fix by dropping this unused flag Reported-by: Stephen Rothwell Fixes: 157ae5ffd76a ("dmaengine: mediatek: Fix a possible deadlock error in mtk_cqdma_tx_status()") Signed-off-by: Vinod Koul

dmaengine: mediatek: Fix a possible deadlock error in mtk_cqdma_tx_status()

2025-05-14T13:54:31+00:00

Fix a potential deadlock bug. Observe that in the mtk-cqdma.c file, functions like mtk_cqdma_issue_pending() and mtk_cqdma_free_active_desc() properly acquire the pc lock before the vc lock when handling pc and vc fields. However, mtk_cqdma_tx_status() violates this order by first acquiring the vc lock before invoking mtk_cqdma_find_active_desc(), which subsequently takes the pc lock. This reversed locking sequence (vc → pc) contradicts the established pc → vc order and creates deadlock risks. Fix the issue by moving the vc lock acquisition code from mtk_cqdma_find_active_desc() to mtk_cqdma_tx_status(). Ensure the pc lock is acquired before the vc lock in the calling function to maintain correct locking hierarchy. Note that since mtk_cqdma_find_active_desc() is a static function with only one caller (mtk_cqdma_tx_status()), this modification safely eliminates the deadlock possibility without affecting other components. This possible bug is found by an experimental static analysis tool developed by our team. This tool analyzes the locking APIs to extract function pairs that can be concurrently executed, and then analyzes the instructions in the paired functions to identify possible concurrency bugs including deadlocks, data races and atomicity violations. Fixes: b1f01e48df5a ("dmaengine: mediatek: Add MediaTek Command-Queue DMA controller for MT6765 SoC") Cc: stable@vger.kernel.org Signed-off-by: Qiu-ji Chen Reviewed-by: AngeloGioacchino Del Regno Link: https://lore.kernel.org/r/20250508073634.3719-1-chenqiuji666@gmail.com Signed-off-by: Vinod Koul

dmaengine: Switch back to struct platform_driver::remove()

2024-10-14T18:20:34+00:00

After commit 0edb555a65d1 ("platform: Make platform_driver::remove() return void") .remove() is (again) the right callback to implement for platform drivers. Convert all platform drivers below drivers/dma after the previous conversion commits apart from the wireless drivers to use .remove(), with the eventual goal to drop struct platform_driver::remove_new(). As .remove() and .remove_new() have the same prototypes, conversion is done by just changing the structure member name in the driver initializer. Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20241004062227.187726-2-u.kleine-koenig@baylibre.com Signed-off-by: Vinod Koul

dmaengine: Fix spelling mistakes

2024-09-02T08:26:01+00:00

Correct spelling mistakes in the DMA engine to improve readability and clarity without altering functionality. Signed-off-by: Amit Vadhavana Reviewed-by: Kees Cook Reviewed-by: Dave Jiang Reviewed-by: Fenghua Yu Link: https://lore.kernel.org/r/20240831172949.13189-1-av2082000@gmail.com Signed-off-by: Vinod Koul

Merge tag 'dmaengine-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine

2023-11-04T04:56:51+00:00

Pull dmaengine updates from Vinod Koul: - Big pile of __counted_by attribute annotations to several structures for bounds checking of flexible arrays at run-time - Another big pile platform remove callback returning void changes - Device tree device_get_match_data() usage and dropping of_match_device() calls - Minor driver updates to pxa, idxd fsl, hisi etc drivers * tag 'dmaengine-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (106 commits) dmaengine: stm32-mdma: correct desc prep when channel running dmaengine: dw-axi-dmac: Add support DMAX_NUM_CHANNELS > 16 dmaengine: xilinx: xilinx_dma: Fix kernel doc about xilinx_dma_remove() dmaengine: mmp_tdma: drop unused variable 'of_id' MAINTAINERS: Add entries for NXP(Freescale) eDMA drivers dmaengine: xilinx: xdma: Support cyclic transfers dmaengine: xilinx: xdma: Prepare the introduction of cyclic transfers dmaengine: Drop unnecessary of_match_device() calls dmaengine: Use device_get_match_data() dmaengine: pxa_dma: Annotate struct pxad_desc_sw with __counted_by dmaengine: pxa_dma: Remove an erroneous BUG_ON() in pxad_free_desc() dmaengine: xilinx: xdma: Use resource_size() in xdma_probe() dmaengine: fsl-dpaa2-qdma: Remove redundant initialization owner in dpaa2_qdma_driver dmaengine: Remove unused declaration dma_chan_cleanup() dmaengine: mmp: fix Wvoid-pointer-to-enum-cast warning dmaengine: qcom: fix Wvoid-pointer-to-enum-cast warning dmaengine: fsl-edma: Remove redundant dev_err() for platform_get_irq() dmaengine: ep93xx_dma: Annotate struct ep93xx_dma_engine with __counted_by dmaengine: idxd: add wq driver name support for accel-config user tool dmaengine: fsl-edma: Annotate struct struct fsl_edma_engine with __counted_by ...

dmaengine: mediatek: Fix deadlock caused by synchronize_irq()

2023-10-04T13:56:36+00:00

The synchronize_irq(c->irq) will not return until the IRQ handler mtk_uart_apdma_irq_handler() is completed. If the synchronize_irq() holds a spin_lock and waits the IRQ handler to complete, but the IRQ handler also needs the same spin_lock. The deadlock will happen. The process is shown below: cpu0 cpu1 mtk_uart_apdma_device_pause() | mtk_uart_apdma_irq_handler() spin_lock_irqsave() | | spin_lock_irqsave() //hold the lock to wait | synchronize_irq() | This patch reorders the synchronize_irq(c->irq) outside the spin_lock in order to mitigate the bug. Fixes: 9135408c3ace ("dmaengine: mediatek: Add MediaTek UART APDMA support") Signed-off-by: Duoming Zhou Reviewed-by: Eugen Hristev Link: https://lore.kernel.org/r/20230806032511.45263-1-duoming@zju.edu.cn Signed-off-by: Vinod Koul

dmaengine: mediatek: mtk-uart-apdma: Convert to platform remove callback returning void

2023-09-28T07:40:50+00:00

The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Eventually after all drivers are converted, .remove_new() is renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König Reviewed-by: AngeloGioacchino Del Regno Link: https://lore.kernel.org/r/20230919133207.1400430-25-u.kleine-koenig@pengutronix.de Signed-off-by: Vinod Koul

dmaengine: mediatek: mtk-hsdma: Convert to platform remove callback returning void

2023-09-28T07:40:50+00:00

The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Eventually after all drivers are converted, .remove_new() is renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König Reviewed-by: AngeloGioacchino Del Regno Link: https://lore.kernel.org/r/20230919133207.1400430-24-u.kleine-koenig@pengutronix.de Signed-off-by: Vinod Koul