kernel/linux.git/drivers/dma/mediatek, branch v6.6.132

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

2026-03-04T12:20:08+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()

2025-09-09T16:56:35+00:00

[ Upstream commit 8eba2187391e5ab49940cd02d6bd45a5617f4daf ] 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 Signed-off-by: Sasha Levin

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

2025-09-09T16:56:31+00:00

[ Upstream commit 157ae5ffd76a2857ccb4b7ce40bc5a344ca00395 ] 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 Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

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: Explicitly include correct DT includes

2023-08-01T18:21:27+00:00

The DT of_device.h and of_platform.h date back to the separate of_platform_bus_type before it as merged into the regular platform bus. As part of that merge prepping Arm DT support 13 years ago, they "temporarily" include each other. They also include platform_device.h and of.h. As a result, there's a pretty much random mix of those include files used throughout the tree. In order to detangle these headers and replace the implicit includes with struct declarations, users need to explicitly include the correct includes. Signed-off-by: Rob Herring Link: https://lore.kernel.org/r/20230718143138.1066177-1-robh@kernel.org Signed-off-by: Vinod Koul

dmaengine: mediatek: drop bogus pm_runtime_set_active()

2023-07-12T16:54:01+00:00

The runtime PM state must be updated while runtime PM is disabled for the change to take effect. Drop the bogus pm_runtime_set_active() which left the PM state set to suspended (as it should be or the clock would not be enabled when the device is resumed). Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20230622075150.885-1-johan+linaro@kernel.org Signed-off-by: Vinod Koul

dmaengine: drivers: Use devm_platform_ioremap_resource()

2023-01-18T16:46:47+00:00

platform_get_resource() and devm_ioremap_resource() are wrapped up in the devm_platform_ioremap_resource() helper. Use the helper and get rid of the local variable for struct resource *. We now have a function call less. Signed-off-by: Tudor Ambarus Acked-by: Jernej Skrabec Acked-by: Peter Ujfalusi Link: https://lore.kernel.org/r/20221110152528.7821-1-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul

dmaengine: mediatek: mtk-hsdma: Fix typo 'the the' in comment

2022-07-26T16:36:05+00:00

Replace 'the the' with 'the' in the comment. Signed-off-by: Slark Xiao Link: https://lore.kernel.org/r/20220721055647.46085-1-slark_xiao@163.com Signed-off-by: Vinod Koul

dmaengine: mediatek-cqdma: fix typo in comment

2022-07-06T05:20:43+00:00

Spelling mistake (triple letters) in comment. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall Link: https://lore.kernel.org/r/20220521111145.81697-61-Julia.Lawall@inria.fr Signed-off-by: Vinod Koul

dmaengine: mediatek: mtk-hsdma: Fix typo in comment

2022-07-01T16:36:55+00:00

Delete the redundant word 'be'. Signed-off-by: Xiang wangx Link: https://lore.kernel.org/r/20220618130120.9783-1-wangxiang@cdjrlc.com Signed-off-by: Vinod Koul