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 11/12] dmaengine: at_xdmac: Remove a level of indentation in at_xdmac_tasklet()
Date: Wed, 15 Dec 2021 13:01:14 +0200 [thread overview]
Message-ID: <20211215110115.191749-12-tudor.ambarus@microchip.com> (raw)
In-Reply-To: <20211215110115.191749-1-tudor.ambarus@microchip.com>
Apart of making the code easier to read, this patch is a prerequisite for
a functional change: tasklets run with interrupts enabled, so we need to
protect atchan->irq_status with spin_lock_irq() otherwise the tasklet can
be interrupted by the IRQ that modifies irq_status. atchan->irq_status
will be protected in a further patch.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
---
drivers/dma/at_xdmac.c | 70 ++++++++++++++++++++----------------------
1 file changed, 34 insertions(+), 36 deletions(-)
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index abe8c4615e65..ba727751a9f6 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1667,53 +1667,51 @@ static void at_xdmac_tasklet(struct tasklet_struct *t)
{
struct at_xdmac_chan *atchan = from_tasklet(atchan, t, tasklet);
struct at_xdmac_desc *desc;
+ struct dma_async_tx_descriptor *txd;
u32 error_mask;
dev_dbg(chan2dev(&atchan->chan), "%s: status=0x%08x\n",
__func__, atchan->irq_status);
- error_mask = AT_XDMAC_CIS_RBEIS
- | AT_XDMAC_CIS_WBEIS
- | AT_XDMAC_CIS_ROIS;
-
- if (at_xdmac_chan_is_cyclic(atchan)) {
- at_xdmac_handle_cyclic(atchan);
- } else if ((atchan->irq_status & AT_XDMAC_CIS_LIS)
- || (atchan->irq_status & error_mask)) {
- struct dma_async_tx_descriptor *txd;
-
- if (atchan->irq_status & error_mask)
- at_xdmac_handle_error(atchan);
-
- spin_lock_irq(&atchan->lock);
- desc = list_first_entry(&atchan->xfers_list,
- struct at_xdmac_desc,
- xfer_node);
- dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
- if (!desc->active_xfer) {
- dev_err(chan2dev(&atchan->chan), "Xfer not active: exiting");
- spin_unlock_irq(&atchan->lock);
- return;
- }
+ if (at_xdmac_chan_is_cyclic(atchan))
+ return at_xdmac_handle_cyclic(atchan);
- txd = &desc->tx_dma_desc;
- dma_cookie_complete(txd);
- /* Remove the transfer from the transfer list. */
- list_del(&desc->xfer_node);
- spin_unlock_irq(&atchan->lock);
+ error_mask = AT_XDMAC_CIS_RBEIS | AT_XDMAC_CIS_WBEIS |
+ AT_XDMAC_CIS_ROIS;
- if (txd->flags & DMA_PREP_INTERRUPT)
- dmaengine_desc_get_callback_invoke(txd, NULL);
+ if (!(atchan->irq_status & AT_XDMAC_CIS_LIS) &&
+ !(atchan->irq_status & error_mask))
+ return;
- dma_run_dependencies(txd);
+ if (atchan->irq_status & error_mask)
+ at_xdmac_handle_error(atchan);
- spin_lock_irq(&atchan->lock);
- /* Move the xfer descriptors into the free descriptors list. */
- list_splice_tail_init(&desc->descs_list,
- &atchan->free_descs_list);
- at_xdmac_advance_work(atchan);
+ spin_lock_irq(&atchan->lock);
+ desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc,
+ xfer_node);
+ dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
+ if (!desc->active_xfer) {
+ dev_err(chan2dev(&atchan->chan), "Xfer not active: exiting");
spin_unlock_irq(&atchan->lock);
+ return;
}
+
+ txd = &desc->tx_dma_desc;
+ dma_cookie_complete(txd);
+ /* Remove the transfer from the transfer list. */
+ list_del(&desc->xfer_node);
+ spin_unlock_irq(&atchan->lock);
+
+ if (txd->flags & DMA_PREP_INTERRUPT)
+ dmaengine_desc_get_callback_invoke(txd, NULL);
+
+ dma_run_dependencies(txd);
+
+ spin_lock_irq(&atchan->lock);
+ /* Move the xfer descriptors into the free descriptors list. */
+ list_splice_tail_init(&desc->descs_list, &atchan->free_descs_list);
+ at_xdmac_advance_work(atchan);
+ spin_unlock_irq(&atchan->lock);
}
static irqreturn_t at_xdmac_interrupt(int irq, void *dev_id)
--
2.25.1
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next prev parent reply other threads:[~2021-12-15 11:15 UTC|newest]
Thread overview: 14+ 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 ` [PATCH v3 01/12] dmaengine: at_xdmac: Don't start transactions at tx_submit level 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 ` [PATCH v3 03/12] dmaengine: at_xdmac: Print debug message after realeasing the lock 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 ` [PATCH v3 05/12] dmaengine: at_xdmac: Fix race for the tx desc callback 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 ` [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 ` [PATCH v3 09/12] dmaengine: at_xdmac: Fix lld view setting 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 [this message]
2021-12-15 11:01 ` [PATCH v3 12/12] dmaengine: at_xdmac: Fix race over irq_status Tudor Ambarus
2022-01-05 10:20 ` [PATCH v3 00/12] dmaengine: at_xdmac: Various fixes Vinod Koul
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