AXI-DMA Backports#3441
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Simplify axi_dmac_parse_dt() by using the cleanup device_node class for automatically releasing the of_node reference when going out of scope. Signed-off-by: Nuno Sá <nuno.sa@analog.com> base-commit: 3980351 change-id: 20251104-axi-dmac-fixes-and-improvs-e3ad512a329c Acked-by: Michael Hennerich <michael.hennerich@analog.com> Link: https://patch.msgid.link/20251104-axi-dmac-fixes-and-improvs-v1-4-3e6fd9328f72@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
…_vec() Document that the DMA_PREP_REPEAT flag can be used with the dmaengine_prep_peripheral_dma_vec() to mark a transfer as cyclic similar to dmaengine_prep_dma_cyclic(). Reviewed-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Nuno Sá <nuno.sa@analog.com> Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-1-0db27b4be95a@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
…ral_dma_vec() Add support for cyclic transfers by checking the DMA_PREP_REPEAT flag. If the flag is set, close the loop and clear the flag for the last segment (the same done for .device_prep_dma_cyclic(). Reviewed-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Nuno Sá <nuno.sa@analog.com> Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-2-0db27b4be95a@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add a new helper for getting the next valid struct axi_dmac_desc. This will be extended in follow up patches to support to gracefully terminate cyclic transfers. Reviewed-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Nuno Sá <nuno.sa@analog.com> Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-3-0db27b4be95a@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
As of now, to terminate a cyclic transfer, one pretty much needs to use brute force and terminate all transfers with .device_terminate_all(). With this change, when a cyclic transfer terminates (and generates an EOT interrupt), look at any new pending transfer with the DMA_PREP_LOAD_EOT flag set. If there is one, the current cyclic transfer is terminated and the next one is enqueued. If the flag is not set, that transfer is ignored. Signed-off-by: Nuno Sá <nuno.sa@analog.com> Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-4-0db27b4be95a@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add support for gracefully terminating hardware cyclic DMA transfers when a new transfer is queued and is flagged with DMA_PREP_LOAD_EOT. Without this, cyclic transfers would continue indefinitely until we brute force it with .device_terminate_all(). When a new descriptor is queued while a cyclic transfer is active, mark the cyclic transfer for termination. For hardware with scatter-gather support, modify the last segment flags to trigger end-of-transfer. For non-SG hardware, clear the CYCLIC flag to allow natural completion. Older IP core versions (pre-4.6.a) can prefetch data when clearing the CYCLIC flag, causing corruption in the next transfer. Work around this by disabling and re-enabling the core to flush prefetched data. The cyclic_eot flag tracks transfers marked for termination, preventing new transfers from starting until the cyclic one completes. Non-EOT transfers submitted after cyclic transfers are discarded with a warning. Also note that for hardware cyclic transfers not using SG, we need to make sure that chan->next_desc is also set to NULL (so we can look at possible EOT transfers) and we also need to move the queue check to after axi_dmac_get_next_desc() because with hardware based cyclic transfers we might get the queue marked as full and hence we would not be able to check for cyclic termination. Signed-off-by: Nuno Sá <nuno.sa@analog.com> Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-5-0db27b4be95a@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Use axi_dmac_free_desc() to free fully the descriptor at fail path when call axi_dmac_alloc_desc() in axi_dmac_prep_peripheral_dma_vec(). Fixes: 74609e5 ("dmaengine: dma-axi-dmac: Implement device_prep_peripheral_dma_vec") Signed-off-by: Nuno Sá <nuno.sa@analog.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260424-dma-dmac-handle-vunmap-v4-2-90f43412fdc0@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
There's no reason to keep struct clk in struct axi_dmac. Hence, use a local clk variable in .probe() and drop it from struct axi_dmac. Signed-off-by: Nuno Sá <nuno.sa@analog.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260424-dma-dmac-handle-vunmap-v4-3-90f43412fdc0@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
This reverts commit 90928c7. Will be fixed in a following patch backported from upstream. Signed-off-by: Nuno Sá <nuno.sa@analog.com>
For architectures like Microblaze or arm64 (where this IP is used), DMA_DIRECT_REMAP is set which means that dma_alloc_coherent() might remap (and hence vmalloc()) some memory. This became visible in a design where dma_direct_use_pool() is not possible. With the above, when calling dma_free_coherent(), vunmap() would be called from softirq context and thus leading to a BUG(). To fix it, use a dma pool that is allocated in .device_alloc_chan_resources() and allocate blocks from it. The key point is that now dma_pool_free() is used in axi_dmac_free_desc() to free the blocks and that just frees the blocks from the pool in the sense they can be used again. In other words, no actual call to dma_free_coherent() happens. That only happens when destroying the pool in axi_dmac_free_chan_resources() which does not happen in any interrupt context. Fixes: 3f8fd25 ("dmaengine: axi-dmac: Allocate hardware descriptors") Signed-off-by: Nuno Sá <nuno.sa@analog.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260424-dma-dmac-handle-vunmap-v4-4-90f43412fdc0@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
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July 16, 2026 08:19
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PR Description
These are important backports (for the new dmabuf API) that we should have in our tree. Also contains some fixes and reverts a custom fix that ended up being done in a different way upstream. Arguably not all commits were strictly needed but given it's a fair amount of patches. bringing them all just made it easier to cherry pick stuff.
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