Hello, On Thu, Sep 21, 2023 at 09:57:11AM +0000, Tim van der Staaij | Zign wrote: > dev_warn internally acquires the lock that is already held when > sdma_update_channel_loop is called. Therefore it is acquired twice and > this is detected as a deadlock. Temporarily release the lock while > logging to avoid this. > > Signed-off-by: Tim van der Staaij <tim.vanderstaaij@xxxxxxxxxxxxx> > Link: https://lore.kernel.org/all/AM0PR08MB308979EC3A8A53AE6E2D3408802CA@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > --- > drivers/dma/imx-sdma.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c > index 51012bd39900..3a7cd783a567 100644 > --- a/drivers/dma/imx-sdma.c > +++ b/drivers/dma/imx-sdma.c > @@ -904,7 +904,10 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac) > * owned buffer is available (i.e. BD_DONE was set too late). > */ > if (sdmac->desc && !is_sdma_channel_enabled(sdmac->sdma, sdmac->channel)) { > + spin_unlock(&sdmac->vc.lock); > dev_warn(sdmac->sdma->dev, "restart cyclic channel %d\n", sdmac->channel); > + spin_lock(&sdmac->vc.lock); > + I don't know if Sascha's patch helps, but this patch looks definitively wrong. If this was the right approach (and I doubt it is) this would definitively lack an explaining code comment. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ |
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