kernel/linux.git/drivers/dma, branch v5.15.209

dmaengine: mxs-dma: Fix missing return value from of_dma_controller_register()

2026-06-01T15:35:34+00:00

[ Upstream commit ab2bf6d4c0a0152907b18d25c1b118ea5ea779df ] Propagate the return value of of_dma_controller_register() in probe() instead of ignoring it. Fixes: a580b8c5429a6 ("dmaengine: mxs-dma: add dma support for i.MX23/28") Signed-off-by: Frank Li Link: https://patch.msgid.link/20260225-mxsdma-module-v3-2-8f798b13baa6@nxp.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

dmaengine: dw-axi-dmac: Remove unnecessary return statement from void function

2026-06-01T15:35:34+00:00

[ Upstream commit 48278a72fce8a8d30efaedeb206c9c3f05c1eb3f ] checkpatch.pl --strict reports a WARNING in dw-axi-dmac-platform.c: WARNING: void function return statements are not generally useful FILE: drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c According to Linux kernel coding style [Documentation/process/ coding-style.rst], explicit "return;" statements at the end of void functions are redundant and should be omitted. The function will automatically return upon reaching the closing brace, so the extra statement adds unnecessary clutter without functional benefit. This patch removes the superfluous "return;" statement in dw_axi_dma_set_hw_channel() to comply with kernel coding standards and eliminate the checkpatch warning. Fixes: 32286e279385 ("dmaengine: dw-axi-dmac: Remove free slot check algorithm in dw_axi_dma_set_hw_channel") Signed-off-by: Khairul Anuar Romli Link: https://patch.msgid.link/20260202060224.12616-4-karom.9560@gmail.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

dmaengine: mmp_pdma: Fix race condition in mmp_pdma_residue()

2026-06-01T15:35:09+00:00

[ Upstream commit a143545855bc2c6e1330f6f57ae375ac44af00a7 ] Add proper locking in mmp_pdma_residue() to prevent use-after-free when accessing descriptor list and descriptor contents. The race occurs when multiple threads call tx_status() while the tasklet on another CPU is freeing completed descriptors: CPU 0 CPU 1 ----- ----- mmp_pdma_tx_status() mmp_pdma_residue() -> NO LOCK held list_for_each_entry(sw, ..) DMA interrupt dma_do_tasklet() -> spin_lock(&desc_lock) list_move(sw->node, ...) spin_unlock(&desc_lock) | dma_pool_free(sw) <- FREED! -> access sw->desc <- UAF! This issue can be reproduced when running dmatest on the same channel with multiple threads (threads_per_chan > 1). Fix by protecting the chain_running list iteration and descriptor access with the chan->desc_lock spinlock. Signed-off-by: Juan Li Signed-off-by: Guodong Xu Link: https://patch.msgid.link/20251216-mmp-pdma-race-v1-1-976a224bb622@riscstar.com Signed-off-by: Vinod Koul [ Minor context conflict resolved. ] Signed-off-by: Wenshan Lan Signed-off-by: Greg Kroah-Hartman

dmaengine: sh: rz-dmac: Protect the driver specific lists

2026-04-18T08:33:38+00:00

[ Upstream commit abb863e6213dc41a58ef8bb3289b7e77460dabf3 ] The driver lists (ld_free, ld_queue) are used in rz_dmac_free_chan_resources(), rz_dmac_terminate_all(), rz_dmac_issue_pending(), and rz_dmac_irq_handler_thread(), all under the virtual channel lock. Take the same lock in rz_dmac_prep_slave_sg() and rz_dmac_prep_dma_memcpy() as well to avoid concurrency issues, since these functions also check whether the lists are empty and update or remove list entries. Fixes: 5000d37042a6 ("dmaengine: sh: Add DMAC driver for RZ/G2L SoC") Cc: stable@vger.kernel.org Reviewed-by: Frank Li Signed-off-by: Claudiu Beznea Link: https://patch.msgid.link/20260316133252.240348-2-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Vinod Koul [ replaced scoped_guard(spinlock_irqsave) with explicit spin_lock_irqsave/spin_unlock_irqrestore calls ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

dmaengine: sh: rz-dmac: Move CHCTRL updates under spinlock

2026-04-18T08:33:38+00:00

[ Upstream commit 89a8567d84bde88cb7cdbbac2ab2299c4f991490 ] Both rz_dmac_disable_hw() and rz_dmac_irq_handle_channel() update the CHCTRL register. To avoid concurrency issues when configuring functionalities exposed by this registers, take the virtual channel lock. All other CHCTRL updates were already protected by the same lock. Previously, rz_dmac_disable_hw() disabled and re-enabled local IRQs, before accessing CHCTRL registers but this does not ensure race-free access. Remove the local IRQ disable/enable code as well. Fixes: 5000d37042a6 ("dmaengine: sh: Add DMAC driver for RZ/G2L SoC") Cc: stable@vger.kernel.org Reviewed-by: Biju Das Reviewed-by: Frank Li Signed-off-by: Claudiu Beznea Link: https://patch.msgid.link/20260316133252.240348-3-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Vinod Koul [ replaced scoped_guard(spinlock_irqsave, ...) ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

dmaengine: xilinx_dma: Fix reset related timeout with two-channel AXIDMA

2026-04-18T08:33:28+00:00

[ Upstream commit a17ce4bc6f4f9acf77ba416c36791a15602e53aa ] A single AXIDMA controller can have one or two channels. When it has two channels, the reset for both are tied together: resetting one channel resets the other as well. This creates a problem where resetting one channel will reset the registers for both channels, including clearing interrupt enable bits for the other channel, which can then lead to timeouts as the driver is waiting for an interrupt which never comes. The driver currently has a probe-time work around for this: when a channel is created, the driver also resets and enables the interrupts. With two channels the reset for the second channel will clear the interrupt enables for the first one. The work around in the driver is just to manually enable the interrupts again in xilinx_dma_alloc_chan_resources(). This workaround only addresses the probe-time issue. When channels are reset at runtime (e.g., in xilinx_dma_terminate_all() or during error recovery), there's no corresponding mechanism to restore the other channel's interrupt enables. This leads to one channel having its interrupts disabled while the driver expects them to work, causing timeouts and DMA failures. A proper fix is a complicated matter, as we should not reset the other channel when it's operating normally. So, perhaps, there should be some kind of synchronization for a common reset, which is not trivial to implement. To add to the complexity, the driver also supports other DMA types, like VDMA, CDMA and MCDMA, which don't have a shared reset. However, when the two-channel AXIDMA is used in the (assumably) normal use case, providing DMA for a single memory-to-memory device, the common reset is a bit smaller issue: when something bad happens on one channel, or when one channel is terminated, the assumption is that we also want to terminate the other channel. And thus resetting both at the same time is "ok". With that line of thinking we can implement a bit better work around than just the current probe time work around: let's enable the AXIDMA interrupts at xilinx_dma_start_transfer() instead. This ensures interrupts are enabled whenever a transfer starts, regardless of any prior resets that may have cleared them. This approach is also more logical: enable interrupts only when needed for a transfer, rather than at resource allocation time, and, I think, all the other DMA types should also use this model, but I'm reluctant to do such changes as I cannot test them. The reset function still enables interrupts even though it's not needed for AXIDMA anymore, but it's common code for all DMA types (VDMA, CDMA, MCDMA), so leave it unchanged to avoid affecting other variants. Signed-off-by: Tomi Valkeinen Fixes: c0bba3a99f07 ("dmaengine: vdma: Add Support for Xilinx AXI Direct Memory Access Engine") Link: https://patch.msgid.link/20260311-xilinx-dma-fix-v2-1-a725abb66e3c@ideasonboard.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

dmaengine: xilinx_dma: Program interrupt delay timeout

2026-04-18T08:33:28+00:00

[ Upstream commit 84b798fedf3fa8f0ab0c096593ba817abc454fe5 ] Program IRQDelay for AXI DMA. The interrupt timeout mechanism causes the DMA engine to generate an interrupt after the delay time period has expired. It enables dmaengine to respond in real-time even though interrupt coalescing is configured. It also remove the placeholder for delay interrupt and merge it with frame completion interrupt. Since by default interrupt delay timeout is disabled this feature addition has no functional impact on VDMA, MCDMA and CDMA IP's. Signed-off-by: Radhey Shyam Pandey Link: https://lore.kernel.org/r/1691387509-2113129-8-git-send-email-radhey.shyam.pandey@amd.com Signed-off-by: Vinod Koul Stable-dep-of: a17ce4bc6f4f ("dmaengine: xilinx_dma: Fix reset related timeout with two-channel AXIDMA") Signed-off-by: Sasha Levin

dmaengine: idxd: Fix freeing the allocated ida too late

2026-04-18T08:33:28+00:00

[ Upstream commit c311f5e9248471a950f0a524c2fd736414d98900 ] It can happen that when the cdev .release() is called, the driver already called ida_destroy(). Move ida_free() to the _del() path. We see with DEBUG_KOBJECT_RELEASE enabled and forcing an early PCI unbind. Fixes: 04922b7445a1 ("dmaengine: idxd: fix cdev setup and free device lifetime issues") Reviewed-by: Dave Jiang Signed-off-by: Vinicius Costa Gomes Link: https://patch.msgid.link/20260121-idxd-fix-flr-on-kernel-queues-v3-v3-9-7ed70658a9d1@intel.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

dmaengine: idxd: Remove usage of the deprecated ida_simple_xx() API

2026-04-18T08:33:28+00:00

[ Upstream commit 1075ee66a8c19bfa375b19c236fd6a22a867f138 ] ida_alloc() and ida_free() should be preferred to the deprecated ida_simple_get() and ida_simple_remove(). This is less verbose. Note that the upper limit of ida_simple_get() is exclusive, but the one of ida_alloc_range() is inclusive. Sothis change allows one more device. MINORMASK is ((1U << MINORBITS) - 1), so allowing MINORMASK as a maximum value makes sense. It is also consistent with other "ida_.*MINORMASK" and "ida_*MINOR()" usages. Signed-off-by: Christophe JAILLET Reviewed-by: Fenghua Yu Acked-by: Lijun Pan Link: https://lore.kernel.org/r/ac991f5f42112fa782a881d391d447529cbc4a23.1702967302.git.christophe.jaillet@wanadoo.fr Signed-off-by: Vinod Koul Stable-dep-of: c311f5e92484 ("dmaengine: idxd: Fix freeing the allocated ida too late") Signed-off-by: Sasha Levin

dmaengine: xilinx: xilinx_dma: Fix unmasked residue subtraction

2026-04-18T08:33:28+00:00

[ Upstream commit c7d812e33f3e8ca0fa9eeabf71d1c7bc3acedc09 ] The segment .control and .status fields both contain top bits which are not part of the buffer size, the buffer size is located only in the bottom max_buffer_len bits. To avoid interference from those top bits, mask out the size using max_buffer_len first, and only then subtract the values. Fixes: a575d0b4e663 ("dmaengine: xilinx_dma: Introduce xilinx_dma_get_residue") Signed-off-by: Marek Vasut Link: https://patch.msgid.link/20260316222530.163815-1-marex@nabladev.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin