[PATCH 6.1 31/42] dmaengine: at_xdmac: disable/enable clock directly on suspend/resume

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Claudiu Beznea <claudiu.beznea@microchip.com>

[ Upstream commit 2de5ddb5e68c94b781b3789bca1ce52000d7d0e0 ]

Runtime PM APIs for at_xdmac just plays with clk_enable()/clk_disable()
letting aside the clk_prepare()/clk_unprepare() that needs to be
executed as the clock is also prepared on probe. Thus instead of using
runtime PM force suspend/resume APIs use
clk_disable_unprepare() + pm_runtime_put_noidle() on suspend and
clk_prepare_enable() + pm_runtime_get_noresume() on resume. This
approach as been chosen instead of using runtime PM force suspend/resume
with clk_unprepare()/clk_prepare() as it looks simpler and the final
code is better.

While at it added the missing pm_runtime_mark_last_busy() on suspend before
decrementing the reference counter.

Fixes: 650b0e990cbd ("dmaengine: at_xdmac: add runtime pm support")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20230214151827.1050280-2-claudiu.beznea@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Stable-dep-of: 44fe8440bda5 ("dmaengine: at_xdmac: do not resume channels paused by consumers")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/dma/at_xdmac.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index bfc8ae2143957..7f7557e4c31d7 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1993,6 +1993,7 @@ static int __maybe_unused atmel_xdmac_suspend(struct device *dev)
 
 	at_xdmac_off(atxdmac);
 	clk_disable_unprepare(atxdmac->clk);
+
 	return 0;
 }
 
@@ -2009,6 +2010,8 @@ static int __maybe_unused atmel_xdmac_resume(struct device *dev)
 	if (ret)
 		return ret;
 
+	pm_runtime_get_noresume(atxdmac->dev);
+
 	at_xdmac_axi_config(pdev);
 
 	/* Clear pending interrupts. */
-- 
2.39.2