diff options
| author |   Tudor Ambarus <tudor.ambarus@microchip.com> | 2021-12-15 13:01:15 +0200 |
|---|---|---|
| committer |   Vinod Koul <vkoul@kernel.org> | 2022-01-05 15:50:04 +0530 |
| commit | e77e561925df2faf77a41896df24a59141a445c9 (patch) | |
| tree | 34a2df65e8a8b362d6511907f9bf74a092b1c492 /drivers/dma/at_xdmac.c | |
| parent | dmaengine: at_xdmac: Remove a level of indentation in at_xdmac_tasklet() (diff) | |
| download | linux-dev-e77e561925df2faf77a41896df24a59141a445c9.tar.xz linux-dev-e77e561925df2faf77a41896df24a59141a445c9.zip | |
dmaengine: at_xdmac: Fix race over irq_status
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. Move the dev_dbg that
prints the irq_status in at_xdmac_handle_cyclic() and lower in
at_xdmac_tasklet() where the IRQ is disabled.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20211215110115.191749-13-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma/at_xdmac.c')
| -rw-r--r-- | drivers/dma/at_xdmac.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index ba727751a9f6..a1da2b4b6d73 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -1611,6 +1611,8 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan) struct dma_async_tx_descriptor *txd; spin_lock_irq(&atchan->lock); + dev_dbg(chan2dev(&atchan->chan), "%s: status=0x%08x\n", + __func__, atchan->irq_status); if (list_empty(&atchan->xfers_list)) { spin_unlock_irq(&atchan->lock); return; @@ -1623,6 +1625,7 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan) dmaengine_desc_get_callback_invoke(txd, NULL); } +/* Called with atchan->lock held. */ static void at_xdmac_handle_error(struct at_xdmac_chan *atchan) { struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device); @@ -1641,8 +1644,6 @@ static void at_xdmac_handle_error(struct at_xdmac_chan *atchan) if (atchan->irq_status & AT_XDMAC_CIS_ROIS) dev_err(chan2dev(&atchan->chan), "request overflow error!!!"); - spin_lock_irq(&atchan->lock); - /* Channel must be disabled first as it's not done automatically */ at_xdmac_write(atxdmac, AT_XDMAC_GD, atchan->mask); while (at_xdmac_read(atxdmac, AT_XDMAC_GS) & atchan->mask) @@ -1652,8 +1653,6 @@ static void at_xdmac_handle_error(struct at_xdmac_chan *atchan) struct at_xdmac_desc, xfer_node); - spin_unlock_irq(&atchan->lock); - /* Print bad descriptor's details if needed */ dev_dbg(chan2dev(&atchan->chan), "%s: lld: mbr_sa=%pad, mbr_da=%pad, mbr_ubc=0x%08x\n", @@ -1670,15 +1669,17 @@ static void at_xdmac_tasklet(struct tasklet_struct *t) struct dma_async_tx_descriptor *txd; u32 error_mask; - dev_dbg(chan2dev(&atchan->chan), "%s: status=0x%08x\n", - __func__, atchan->irq_status); - if (at_xdmac_chan_is_cyclic(atchan)) return at_xdmac_handle_cyclic(atchan); error_mask = AT_XDMAC_CIS_RBEIS | AT_XDMAC_CIS_WBEIS | AT_XDMAC_CIS_ROIS; + spin_lock_irq(&atchan->lock); + + dev_dbg(chan2dev(&atchan->chan), "%s: status=0x%08x\n", + __func__, atchan->irq_status); + if (!(atchan->irq_status & AT_XDMAC_CIS_LIS) && !(atchan->irq_status & error_mask)) return; @@ -1686,7 +1687,6 @@ static void at_xdmac_tasklet(struct tasklet_struct *t) 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); |