diff options
| author | Stefan Wahren <wahrenst@gmx.net> | 2024-12-04 17:55:46 +0100 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2024-12-24 15:37:19 +0530 |
| commit | 9602a843cb3a16df8930eb9b046aa7aeb769521b (patch) | |
| tree | e738e3e1549413dddddb20f76327094644b15228 /drivers/dma/bcm2835-dma.c | |
| parent | 68811c928f88828f188656dd3c9c184eeec2ce86 (diff) | |
dmaengine: bcm2835-dma: Prevent suspend if DMA channel is busy
bcm2835-dma provides the service to others, so it should suspend
late and resume early. Suspend should be prevented in case a DMA
channel is still busy.
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20241204165546.77941-1-wahrenst@gmx.net
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma/bcm2835-dma.c')
| -rw-r--r-- | drivers/dma/bcm2835-dma.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c index 7ba52dee40a9..20b10c15c696 100644 --- a/drivers/dma/bcm2835-dma.c +++ b/drivers/dma/bcm2835-dma.c @@ -875,6 +875,27 @@ static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec, return chan; } +static int bcm2835_dma_suspend_late(struct device *dev) +{ + struct bcm2835_dmadev *od = dev_get_drvdata(dev); + struct bcm2835_chan *c, *next; + + list_for_each_entry_safe(c, next, &od->ddev.channels, + vc.chan.device_node) { + void __iomem *chan_base = c->chan_base; + + /* Check if DMA channel is busy */ + if (readl(chan_base + BCM2835_DMA_ADDR)) + return -EBUSY; + } + + return 0; +} + +static const struct dev_pm_ops bcm2835_dma_pm_ops = { + SET_LATE_SYSTEM_SLEEP_PM_OPS(bcm2835_dma_suspend_late, NULL) +}; + static int bcm2835_dma_probe(struct platform_device *pdev) { struct bcm2835_dmadev *od; @@ -1033,6 +1054,7 @@ static struct platform_driver bcm2835_dma_driver = { .driver = { .name = "bcm2835-dma", .of_match_table = of_match_ptr(bcm2835_dma_of_match), + .pm = pm_ptr(&bcm2835_dma_pm_ops), }, }; |