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| author | Sascha Hauer <s.hauer@pengutronix.de> | 2019-12-16 11:53:21 +0100 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2019-12-26 05:34:18 +0100 |
| commit | 51fe9cd2bd92d95fc200385187d346e293ceefc9 (patch) | |
| tree | a246a3539224a5adc2cf2f899ac47f93f407acb8 /drivers/dma/dw-axi-dmac | |
| parent | dmaengine: bcm2835: do not call vchan_vdesc_fini() with lock held (diff) | |
| download | linux-51fe9cd2bd92d95fc200385187d346e293ceefc9.tar.xz linux-51fe9cd2bd92d95fc200385187d346e293ceefc9.zip | |
dmaengine: virt-dma: Add missing locking
Originally freeing descriptors was split into a locked and an unlocked
part. The locked part in vchan_get_all_descriptors() collected all
descriptors on a separate list_head. This was done to allow iterating
over that new list in vchan_dma_desc_free_list() without a lock held.
This became broken in 13bb26ae8850 ("dmaengine: virt-dma: don't always
free descriptor upon completion"). With this commit
vchan_dma_desc_free_list() no longer exclusively operates on the
separate list, but starts to put descriptors which can be reused back on
&vc->desc_allocated. This list operation should have been locked, but
wasn't.
In the mean time drivers started to call vchan_dma_desc_free_list() with
their lock held so that we now have the situation that
vchan_dma_desc_free_list() is called locked from some drivers and
unlocked from others.
To clean this up we have to do two things:
1. Add missing locking in vchan_dma_desc_free_list()
2. Make sure drivers call vchan_dma_desc_free_list() unlocked
This needs to be done atomically, so in this patch the locking is added
and all drivers are fixed.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Green Wan <green.wan@sifive.com>
Tested-by: Green Wan <green.wan@sifive.com>
Link: https://lore.kernel.org/r/20191216105328.15198-3-s.hauer@pengutronix.de
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma/dw-axi-dmac')
| -rw-r--r-- | drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c index a1ce307c502f..14c1ac26f866 100644 --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c @@ -636,14 +636,10 @@ static int dma_chan_terminate_all(struct dma_chan *dchan) vchan_get_all_descriptors(&chan->vc, &head); - /* - * As vchan_dma_desc_free_list can access to desc_allocated list - * we need to call it in vc.lock context. - */ - vchan_dma_desc_free_list(&chan->vc, &head); - spin_unlock_irqrestore(&chan->vc.lock, flags); + vchan_dma_desc_free_list(&chan->vc, &head); + dev_vdbg(dchan2dev(dchan), "terminated: %s\n", axi_chan_name(chan)); return 0; |