| Message ID | 20171114143212.8311-6-peter.ujfalusi@ti.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
Peter Ujfalusi <peter.ujfalusi@ti.com> writes: > To avoid race with vchan_complete, use the race free way to terminate > running transfer. > > Implement the device_synchronize callback to make sure that the terminated > descriptor is freed. > > CC: Martin Sperl <kernel@martin.sperl.org> > CC: Eric Anholt <eric@anholt.net> > Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> I haven't fully followed the series, but thanks for porting your fix to other platforms! Acked-by: Eric Anholt <eric@anholt.net>
Eric, On 11/15/2017 08:53 PM, Eric Anholt wrote: > Peter Ujfalusi <peter.ujfalusi@ti.com> writes: > >> To avoid race with vchan_complete, use the race free way to terminate >> running transfer. >> >> Implement the device_synchronize callback to make sure that the terminated >> descriptor is freed. >> >> CC: Martin Sperl <kernel@martin.sperl.org> >> CC: Eric Anholt <eric@anholt.net> >> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> > > I haven't fully followed the series, but thanks for porting your fix to > other platforms! I have seen similar patterns in these drivers and it was the right thing to do imho. Unfortunately I can not test on other platforms than eDMA and sDMA, but I firmly believe that based on the usage it should be fine as it survives my torture tests. It would be great to see some Tested-by from others to have more coverage. > Acked-by: Eric Anholt <eric@anholt.net> Thank you!
diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c index 6204cc32d09c..847f84a41a69 100644 --- a/drivers/dma/bcm2835-dma.c +++ b/drivers/dma/bcm2835-dma.c @@ -812,7 +812,7 @@ static int bcm2835_dma_terminate_all(struct dma_chan *chan) * c->desc is NULL and exit.) */ if (c->desc) { - bcm2835_dma_desc_free(&c->desc->vd); + vchan_terminate_vdesc(&c->desc->vd); c->desc = NULL; bcm2835_dma_abort(c->chan_base); @@ -836,6 +836,13 @@ static int bcm2835_dma_terminate_all(struct dma_chan *chan) return 0; } +static void bcm2835_dma_synchronize(struct dma_chan *chan) +{ + struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); + + vchan_synchronize(&c->vc); +} + static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id, int irq, unsigned int irq_flags) { @@ -942,6 +949,7 @@ static int bcm2835_dma_probe(struct platform_device *pdev) od->ddev.device_prep_dma_memcpy = bcm2835_dma_prep_dma_memcpy; od->ddev.device_config = bcm2835_dma_slave_config; od->ddev.device_terminate_all = bcm2835_dma_terminate_all; + od->ddev.device_synchronize = bcm2835_dma_synchronize; od->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); od->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
To avoid race with vchan_complete, use the race free way to terminate running transfer. Implement the device_synchronize callback to make sure that the terminated descriptor is freed. CC: Martin Sperl <kernel@martin.sperl.org> CC: Eric Anholt <eric@anholt.net> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> --- drivers/dma/bcm2835-dma.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)