linux-kernel - [PATCH 1/7] dmaengine: at_xdmac: disable/enable clock directly on suspend/resume

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230214151827.1050280-2-claudiu.beznea@microchip.com>
Date:   Tue, 14 Feb 2023 17:18:21 +0200
From:   Claudiu Beznea <claudiu.beznea@...rochip.com>
To:     <ludovic.desroches@...rochip.com>, <tudor.ambarus@...aro.org>,
        <vkoul@...nel.org>, <nicolas.ferre@...rochip.com>
CC:     <linux-arm-kernel@...ts.infradead.org>,
        <dmaengine@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        Claudiu Beznea <claudiu.beznea@...rochip.com>
Subject: [PATCH 1/7] dmaengine: at_xdmac: disable/enable clock directly on suspend/resume

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@...rochip.com>
---
 drivers/dma/at_xdmac.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 1f0fab180f8f..f654ecaafb90 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -2130,7 +2130,11 @@ static int __maybe_unused atmel_xdmac_suspend(struct device *dev)
 	atxdmac->save_gim = at_xdmac_read(atxdmac, AT_XDMAC_GIM);
 
 	at_xdmac_off(atxdmac);
-	return pm_runtime_force_suspend(atxdmac->dev);
+	pm_runtime_mark_last_busy(atxdmac->dev);
+	pm_runtime_put_noidle(atxdmac->dev);
+	clk_disable_unprepare(atxdmac->clk);
+
+	return 0;
 }
 
 static int __maybe_unused atmel_xdmac_resume(struct device *dev)
@@ -2142,10 +2146,12 @@ static int __maybe_unused atmel_xdmac_resume(struct device *dev)
 	int			i;
 	int ret;
 
-	ret = pm_runtime_force_resume(atxdmac->dev);
-	if (ret < 0)
+	ret = clk_prepare_enable(atxdmac->clk);
+	if (ret)
 		return ret;
 
+	pm_runtime_get_noresume(atxdmac->dev);
+
 	at_xdmac_axi_config(pdev);
 
 	/* Clear pending interrupts. */
-- 
2.34.1