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authorTony Lindgren <tony@atomide.com>2020-11-09 18:40:13 +0300
committerVinod Koul <vkoul@kernel.org>2020-11-10 15:44:09 +0300
commit29a25b9246f7f24203d30d59424cbe22bd905dfc (patch)
treec8325ffc4b858238f348b268649295a7dcc3a875 /drivers/dma
parent96d5d884f78306206d745d856aad322becd100c3 (diff)
downloadlinux-29a25b9246f7f24203d30d59424cbe22bd905dfc.tar.xz
dmaengine: ti: omap-dma: Block PM if SDMA is busy to fix audio
We now use cpu_pm for saving and restoring device context for deeper SoC idle states. But for omap3, we must also block idle if SDMA is busy. If we don't block idle when SDMA is busy, we eventually end up saving and restoring SDMA register state on PER domain idle while SDMA is active and that causes at least audio playback to fail. Fixes: 4c74ecf79227 ("dmaengine: ti: omap-dma: Add device tree match data and use it for cpu_pm") Reported-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Link: https://lore.kernel.org/r/20201109154013.11950-1-tony@atomide.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/ti/omap-dma.c37
1 files changed, 24 insertions, 13 deletions
diff --git a/drivers/dma/ti/omap-dma.c b/drivers/dma/ti/omap-dma.c
index c9fe5e3a6b55..268a08058714 100644
--- a/drivers/dma/ti/omap-dma.c
+++ b/drivers/dma/ti/omap-dma.c
@@ -1522,29 +1522,38 @@ static void omap_dma_free(struct omap_dmadev *od)
}
}
+/* Currently used by omap2 & 3 to block deeper SoC idle states */
+static bool omap_dma_busy(struct omap_dmadev *od)
+{
+ struct omap_chan *c;
+ int lch = -1;
+
+ while (1) {
+ lch = find_next_bit(od->lch_bitmap, od->lch_count, lch + 1);
+ if (lch >= od->lch_count)
+ break;
+ c = od->lch_map[lch];
+ if (!c)
+ continue;
+ if (omap_dma_chan_read(c, CCR) & CCR_ENABLE)
+ return true;
+ }
+
+ return false;
+}
+
/* Currently only used for omap2. For omap1, also a check for lcd_dma is needed */
static int omap_dma_busy_notifier(struct notifier_block *nb,
unsigned long cmd, void *v)
{
struct omap_dmadev *od;
- struct omap_chan *c;
- int lch = -1;
od = container_of(nb, struct omap_dmadev, nb);
switch (cmd) {
case CPU_CLUSTER_PM_ENTER:
- while (1) {
- lch = find_next_bit(od->lch_bitmap, od->lch_count,
- lch + 1);
- if (lch >= od->lch_count)
- break;
- c = od->lch_map[lch];
- if (!c)
- continue;
- if (omap_dma_chan_read(c, CCR) & CCR_ENABLE)
- return NOTIFY_BAD;
- }
+ if (omap_dma_busy(od))
+ return NOTIFY_BAD;
break;
case CPU_CLUSTER_PM_ENTER_FAILED:
case CPU_CLUSTER_PM_EXIT:
@@ -1595,6 +1604,8 @@ static int omap_dma_context_notifier(struct notifier_block *nb,
switch (cmd) {
case CPU_CLUSTER_PM_ENTER:
+ if (omap_dma_busy(od))
+ return NOTIFY_BAD;
omap_dma_context_save(od);
break;
case CPU_CLUSTER_PM_ENTER_FAILED: