This is a note to let you know that I've just added the patch titled
dmaengine: at_xdmac: fix imbalanced runtime PM reference counter
to the 6.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dmaengine-at_xdmac-fix-imbalanced-runtime-pm-referen.patch
and it can be found in the queue-6.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9e01b6de35dd0b370bb388a64d56f1f85dc15526
Author: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
Date: Tue Feb 14 17:18:22 2023 +0200
dmaengine: at_xdmac: fix imbalanced runtime PM reference counter
[ Upstream commit e53957e1ec5196671e49a48f90a5c9555153189a ]
In case there are channels not paused during suspend (which on AT91 case
is valid for serial driver when no_console_suspend boot argument is used)
the at_xdmac_runtime_suspend_descriptors() was called more than
one time due to at_xdmac_off(). To fix this add a new argument to
at_xdmac_off() to specify if runtime PM reference counter needs to be
decremented for queued active descriptors. Along with it moved the
at_xdmac_runtime_suspend_descriptors() call under at_xdmac_chan_is_paused()
check on suspend path as for the rest of channels the suspend is delayed
by atmel_xdmac_prepare() in case channel is enabled. Same approach has
been applied on resume path.
Fixes: 650b0e990cbd ("dmaengine: at_xdmac: add runtime pm support")
Signed-off-by: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230214151827.1050280-3-claudiu.beznea@xxxxxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index f654ecaafb906..af3b494f9ba9b 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -412,7 +412,7 @@ static bool at_xdmac_chan_is_enabled(struct at_xdmac_chan *atchan)
return ret;
}
-static void at_xdmac_off(struct at_xdmac *atxdmac)
+static void at_xdmac_off(struct at_xdmac *atxdmac, bool suspend_descriptors)
{
struct dma_chan *chan, *_chan;
struct at_xdmac_chan *atchan;
@@ -431,7 +431,7 @@ static void at_xdmac_off(struct at_xdmac *atxdmac)
at_xdmac_write(atxdmac, AT_XDMAC_GID, -1L);
/* Decrement runtime PM ref counter for each active descriptor. */
- if (!list_empty(&atxdmac->dma.channels)) {
+ if (!list_empty(&atxdmac->dma.channels) && suspend_descriptors) {
list_for_each_entry_safe(chan, _chan, &atxdmac->dma.channels,
device_node) {
atchan = to_at_xdmac_chan(chan);
@@ -2118,18 +2118,18 @@ static int __maybe_unused atmel_xdmac_suspend(struct device *dev)
atchan->save_cc = at_xdmac_chan_read(atchan, AT_XDMAC_CC);
if (at_xdmac_chan_is_cyclic(atchan)) {
- if (!at_xdmac_chan_is_paused(atchan))
+ if (!at_xdmac_chan_is_paused(atchan)) {
at_xdmac_device_pause(chan);
+ at_xdmac_runtime_suspend_descriptors(atchan);
+ }
atchan->save_cim = at_xdmac_chan_read(atchan, AT_XDMAC_CIM);
atchan->save_cnda = at_xdmac_chan_read(atchan, AT_XDMAC_CNDA);
atchan->save_cndc = at_xdmac_chan_read(atchan, AT_XDMAC_CNDC);
}
-
- at_xdmac_runtime_suspend_descriptors(atchan);
}
atxdmac->save_gim = at_xdmac_read(atxdmac, AT_XDMAC_GIM);
- at_xdmac_off(atxdmac);
+ at_xdmac_off(atxdmac, false);
pm_runtime_mark_last_busy(atxdmac->dev);
pm_runtime_put_noidle(atxdmac->dev);
clk_disable_unprepare(atxdmac->clk);
@@ -2165,14 +2165,14 @@ static int __maybe_unused atmel_xdmac_resume(struct device *dev)
list_for_each_entry_safe(chan, _chan, &atxdmac->dma.channels, device_node) {
atchan = to_at_xdmac_chan(chan);
- ret = at_xdmac_runtime_resume_descriptors(atchan);
- if (ret < 0)
- return ret;
-
at_xdmac_chan_write(atchan, AT_XDMAC_CC, atchan->save_cc);
if (at_xdmac_chan_is_cyclic(atchan)) {
- if (at_xdmac_chan_is_paused(atchan))
+ if (at_xdmac_chan_is_paused(atchan)) {
+ ret = at_xdmac_runtime_resume_descriptors(atchan);
+ if (ret < 0)
+ return ret;
at_xdmac_device_resume(chan);
+ }
at_xdmac_chan_write(atchan, AT_XDMAC_CNDA, atchan->save_cnda);
at_xdmac_chan_write(atchan, AT_XDMAC_CNDC, atchan->save_cndc);
at_xdmac_chan_write(atchan, AT_XDMAC_CIE, atchan->save_cim);
@@ -2318,7 +2318,7 @@ static int at_xdmac_probe(struct platform_device *pdev)
INIT_LIST_HEAD(&atxdmac->dma.channels);
/* Disable all chans and interrupts. */
- at_xdmac_off(atxdmac);
+ at_xdmac_off(atxdmac, true);
for (i = 0; i < nr_channels; i++) {
struct at_xdmac_chan *atchan = &atxdmac->chan[i];
@@ -2382,7 +2382,7 @@ static int at_xdmac_remove(struct platform_device *pdev)
struct at_xdmac *atxdmac = (struct at_xdmac *)platform_get_drvdata(pdev);
int i;
- at_xdmac_off(atxdmac);
+ at_xdmac_off(atxdmac, true);
of_dma_controller_free(pdev->dev.of_node);
dma_async_device_unregister(&atxdmac->dma);
pm_runtime_disable(atxdmac->dev);
