From e53957e1ec5196671e49a48f90a5c9555153189a Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Tue, 14 Feb 2023 17:18:22 +0200 Subject: [PATCH] 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: 650b0e990cbd ("dmaengine: at_xdmac: add runtime pm support") Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20230214151827.1050280-3-claudiu.beznea@microchip.com Signed-off-by: Vinod Koul --- drivers/dma/at_xdmac.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index f654ecaafb90..af3b494f9ba9 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);