Hi Vishal, On 2/27/24 23:21, Vishal Sagar wrote: > From: Neel Gandhi <neel.gandhi@xxxxxxxxxx> > > The vchan_next_desc() function, called from > xilinx_dpdma_chan_queue_transfer(), must be called with > virt_dma_chan.lock held. This isn't correctly handled in all code paths, > resulting in a race condition between the .device_issue_pending() > handler and the IRQ handler which causes DMA to randomly stop. Fix it by > taking the lock around xilinx_dpdma_chan_queue_transfer() calls that are > missing it. > > Signed-off-by: Neel Gandhi <neel.gandhi@xxxxxxx> > Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xxxxxxx> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx> > Signed-off-by: Vishal Sagar <vishal.sagar@xxxxxxx> > > Link: https://cas5-0-urlprotect.trendmicro.com:443/wis/clicktime/v1/query?url=https%3a%2f%2flore.kernel.org%2fall%2f20220122121407.11467%2d1%2dneel.gandhi%40xilinx.com&umid=a486940f-2fe3-47f4-9b3f-416e59036eab&auth=d807158c60b7d2502abde8a2fc01f40662980862-a75e22540e8429d70f26093b45d38995a0e6e1e8 > --- > drivers/dma/xilinx/xilinx_dpdma.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/dma/xilinx/xilinx_dpdma.c b/drivers/dma/xilinx/xilinx_dpdma.c > index b82815e64d24..28d9af8f00f0 100644 > --- a/drivers/dma/xilinx/xilinx_dpdma.c > +++ b/drivers/dma/xilinx/xilinx_dpdma.c > @@ -1097,12 +1097,14 @@ static void xilinx_dpdma_chan_vsync_irq(struct xilinx_dpdma_chan *chan) > * Complete the active descriptor, if any, promote the pending > * descriptor to active, and queue the next transfer, if any. > */ > + spin_lock(&chan->vchan.lock); > if (chan->desc.active) > vchan_cookie_complete(&chan->desc.active->vdesc); > chan->desc.active = pending; > chan->desc.pending = NULL; > > xilinx_dpdma_chan_queue_transfer(chan); > + spin_unlock(&chan->vchan.lock); > > out: > spin_unlock_irqrestore(&chan->lock, flags); > @@ -1264,10 +1266,12 @@ static void xilinx_dpdma_issue_pending(struct dma_chan *dchan) > struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan); > unsigned long flags; > > - spin_lock_irqsave(&chan->vchan.lock, flags); > + spin_lock_irqsave(&chan->lock, flags); > + spin_lock(&chan->vchan.lock); > if (vchan_issue_pending(&chan->vchan)) > xilinx_dpdma_chan_queue_transfer(chan); > - spin_unlock_irqrestore(&chan->vchan.lock, flags); > + spin_unlock(&chan->vchan.lock); > + spin_unlock_irqrestore(&chan->lock, flags); > } > > static int xilinx_dpdma_config(struct dma_chan *dchan, > @@ -1495,7 +1499,9 @@ static void xilinx_dpdma_chan_err_task(struct tasklet_struct *t) > XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id); > > spin_lock_irqsave(&chan->lock, flags); > + spin_lock(&chan->vchan.lock); > xilinx_dpdma_chan_queue_transfer(chan); > + spin_unlock(&chan->vchan.lock); > spin_unlock_irqrestore(&chan->lock, flags); > } I also ran into this issue and came up with the same fix [1]. Reviewed-by: Sean Anderson <sean.anderson@xxxxxxxxx> [1] https://lore.kernel.org/dmaengine/20240308210034.3634938-2-sean.anderson@xxxxxxxxx/
