Commit e53957e1 authored by Claudiu Beznea's avatar Claudiu Beznea Committed by Vinod Koul
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dmaengine: at_xdmac: fix imbalanced runtime PM reference counter 



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: 650b0e99 ("dmaengine: at_xdmac: add runtime pm support")
Signed-off-by: default avatarClaudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20230214151827.1050280-3-claudiu.beznea@microchip.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 2de5ddb5

drivers/dma/at_xdmac.c

+13 −13
Original line number Diff line number Diff line
@@ -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);



		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)) {

				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))

				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);