From: Tudor Ambarus <tudor.ambarus@microchip.com> To: <vkoul@kernel.org> Cc: <ludovic.desroches@microchip.com>, <nicolas.ferre@microchip.com>, <mripard@kernel.org>, <linux-arm-kernel@lists.infradead.org>, <dmaengine@vger.kernel.org>, <linux-kernel@vger.kernel.org>, Tudor Ambarus <tudor.ambarus@microchip.com> Subject: [PATCH v3 07/12] dmaengine: at_xdmac: Fix concurrency over xfers_list Date: Wed, 15 Dec 2021 13:01:10 +0200 [thread overview] Message-ID: <20211215110115.191749-8-tudor.ambarus@microchip.com> (raw) In-Reply-To: <20211215110115.191749-1-tudor.ambarus@microchip.com> 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 <tudor.ambarus@microchip.com> --- drivers/dma/at_xdmac.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index b6547f1b5645..eeb03065d484 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -1608,14 +1608,17 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan) struct at_xdmac_desc *desc; struct dma_async_tx_descriptor *txd; - if (!list_empty(&atchan->xfers_list)) { - desc = list_first_entry(&atchan->xfers_list, - struct at_xdmac_desc, xfer_node); - txd = &desc->tx_dma_desc; - - if (txd->flags & DMA_PREP_INTERRUPT) - dmaengine_desc_get_callback_invoke(txd, NULL); + spin_lock_irq(&atchan->lock); + if (list_empty(&atchan->xfers_list)) { + spin_unlock_irq(&atchan->lock); + return; } + desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc, + xfer_node); + spin_unlock_irq(&atchan->lock); + txd = &desc->tx_dma_desc; + if (txd->flags & DMA_PREP_INTERRUPT) + dmaengine_desc_get_callback_invoke(txd, NULL); } static void at_xdmac_handle_error(struct at_xdmac_chan *atchan) -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: Tudor Ambarus <tudor.ambarus@microchip.com> To: <vkoul@kernel.org> Cc: Tudor Ambarus <tudor.ambarus@microchip.com>, mripard@kernel.org, linux-kernel@vger.kernel.org, ludovic.desroches@microchip.com, dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 07/12] dmaengine: at_xdmac: Fix concurrency over xfers_list Date: Wed, 15 Dec 2021 13:01:10 +0200 [thread overview] Message-ID: <20211215110115.191749-8-tudor.ambarus@microchip.com> (raw) In-Reply-To: <20211215110115.191749-1-tudor.ambarus@microchip.com> 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 <tudor.ambarus@microchip.com> --- drivers/dma/at_xdmac.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index b6547f1b5645..eeb03065d484 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -1608,14 +1608,17 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan) struct at_xdmac_desc *desc; struct dma_async_tx_descriptor *txd; - if (!list_empty(&atchan->xfers_list)) { - desc = list_first_entry(&atchan->xfers_list, - struct at_xdmac_desc, xfer_node); - txd = &desc->tx_dma_desc; - - if (txd->flags & DMA_PREP_INTERRUPT) - dmaengine_desc_get_callback_invoke(txd, NULL); + spin_lock_irq(&atchan->lock); + if (list_empty(&atchan->xfers_list)) { + spin_unlock_irq(&atchan->lock); + return; } + desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc, + xfer_node); + spin_unlock_irq(&atchan->lock); + txd = &desc->tx_dma_desc; + if (txd->flags & DMA_PREP_INTERRUPT) + dmaengine_desc_get_callback_invoke(txd, NULL); } static void at_xdmac_handle_error(struct at_xdmac_chan *atchan) -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-12-15 11:01 UTC|newest] Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-12-15 11:01 [PATCH v3 00/12] dmaengine: at_xdmac: Various fixes Tudor Ambarus 2021-12-15 11:01 ` Tudor Ambarus 2021-12-15 11:01 ` [PATCH v3 01/12] dmaengine: at_xdmac: Don't start transactions at tx_submit level Tudor Ambarus 2021-12-15 11:01 ` Tudor Ambarus 2021-12-15 11:01 ` [PATCH v3 02/12] dmaengine: at_xdmac: Start transfer for cyclic channels in issue_pending Tudor Ambarus 2021-12-15 11:01 ` Tudor Ambarus 2021-12-15 11:01 ` [PATCH v3 03/12] dmaengine: at_xdmac: Print debug message after realeasing the lock Tudor Ambarus 2021-12-15 11:01 ` Tudor Ambarus 2021-12-15 11:01 ` [PATCH v3 04/12] dmaengine: at_xdmac: Fix concurrency over chan's completed_cookie Tudor Ambarus 2021-12-15 11:01 ` Tudor Ambarus 2021-12-15 11:01 ` [PATCH v3 05/12] dmaengine: at_xdmac: Fix race for the tx desc callback Tudor Ambarus 2021-12-15 11:01 ` Tudor Ambarus 2021-12-15 11:01 ` [PATCH v3 06/12] dmaengine: at_xdmac: Move the free desc to the tail of the desc list Tudor Ambarus 2021-12-15 11:01 ` Tudor Ambarus 2021-12-15 11:01 ` Tudor Ambarus [this message] 2021-12-15 11:01 ` [PATCH v3 07/12] dmaengine: at_xdmac: Fix concurrency over xfers_list Tudor Ambarus 2021-12-15 11:01 ` [PATCH v3 08/12] dmaengine: at_xdmac: Remove a level of indentation in at_xdmac_advance_work() Tudor Ambarus 2021-12-15 11:01 ` Tudor Ambarus 2021-12-15 11:01 ` [PATCH v3 09/12] dmaengine: at_xdmac: Fix lld view setting Tudor Ambarus 2021-12-15 11:01 ` Tudor Ambarus 2021-12-15 11:01 ` [PATCH v3 10/12] dmaengine: at_xdmac: Fix at_xdmac_lld struct definition Tudor Ambarus 2021-12-15 11:01 ` Tudor Ambarus 2021-12-15 11:01 ` [PATCH v3 11/12] dmaengine: at_xdmac: Remove a level of indentation in at_xdmac_tasklet() Tudor Ambarus 2021-12-15 11:01 ` Tudor Ambarus 2021-12-15 11:01 ` [PATCH v3 12/12] dmaengine: at_xdmac: Fix race over irq_status Tudor Ambarus 2021-12-15 11:01 ` Tudor Ambarus 2022-01-05 10:20 ` [PATCH v3 00/12] dmaengine: at_xdmac: Various fixes Vinod Koul 2022-01-05 10:20 ` Vinod Koul
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