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From: Kamal Dasu <kdasu.kdev@gmail.com>
To: ulf.hansson@linaro.org, robh+dt@kernel.org, krzk+dt@kernel.org,
	alcooperx@gmail.com
Cc: f.fainelli@gmail.com, bcm-kernel-feedback-list@broadcom.com,
	adrian.hunter@intel.com, linux-mmc@vger.kernel.org,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	Kamal Dasu <kdasu.kdev@gmail.com>
Subject: [PATCH] mmc: sdhci-brcmstb: use clk_get_rate(base_clk) in PM resume
Date: Thu, 14 Jul 2022 13:41:32 -0400	[thread overview]
Message-ID: <20220714174132.18541-1-kdasu.kdev@gmail.com> (raw)

Use clk_get_rate for base_clk on resume before setting new rate.
This change ensures that the clock api returns current rate
and sets the clock to the desired rate and honors CLK_GET_NO_CACHE
attribute used by clock api.

Fixes: 97904a59855c (mmc: sdhci-brcmstb: Add ability to increase max clock rate for 72116b0)
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
---
 drivers/mmc/host/sdhci-brcmstb.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-brcmstb.c b/drivers/mmc/host/sdhci-brcmstb.c
index 28e9cf995c41..aff36a933ebe 100644
--- a/drivers/mmc/host/sdhci-brcmstb.c
+++ b/drivers/mmc/host/sdhci-brcmstb.c
@@ -406,7 +406,14 @@ static int sdhci_brcmstb_resume(struct device *dev)
 	ret = sdhci_pltfm_resume(dev);
 	if (!ret && priv->base_freq_hz) {
 		ret = clk_prepare_enable(priv->base_clk);
-		if (!ret)
+		/*
+		 * Note: using clk_get_rate() below as clk_get_rate()
+		 * honors CLK_GET_RATE_NOCACHE attribute, but clk_set_rate()
+		 * may do implicit get_rate() calls that do not honor
+		 * CLK_GET_RATE_NOCACHE.
+		 */
+		if (!ret &&
+		    (clk_get_rate(priv->base_clk) != priv->base_freq_hz))
 			ret = clk_set_rate(priv->base_clk, priv->base_freq_hz);
 	}
 
-- 
2.17.1


WARNING: multiple messages have this Message-ID (diff)
From: Kamal Dasu <kdasu.kdev@gmail.com>
To: ulf.hansson@linaro.org, robh+dt@kernel.org, krzk+dt@kernel.org,
	alcooperx@gmail.com
Cc: f.fainelli@gmail.com, bcm-kernel-feedback-list@broadcom.com,
	adrian.hunter@intel.com, linux-mmc@vger.kernel.org,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	Kamal Dasu <kdasu.kdev@gmail.com>
Subject: [PATCH] mmc: sdhci-brcmstb: use clk_get_rate(base_clk) in PM resume
Date: Thu, 14 Jul 2022 13:41:32 -0400	[thread overview]
Message-ID: <20220714174132.18541-1-kdasu.kdev@gmail.com> (raw)

Use clk_get_rate for base_clk on resume before setting new rate.
This change ensures that the clock api returns current rate
and sets the clock to the desired rate and honors CLK_GET_NO_CACHE
attribute used by clock api.

Fixes: 97904a59855c (mmc: sdhci-brcmstb: Add ability to increase max clock rate for 72116b0)
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
---
 drivers/mmc/host/sdhci-brcmstb.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-brcmstb.c b/drivers/mmc/host/sdhci-brcmstb.c
index 28e9cf995c41..aff36a933ebe 100644
--- a/drivers/mmc/host/sdhci-brcmstb.c
+++ b/drivers/mmc/host/sdhci-brcmstb.c
@@ -406,7 +406,14 @@ static int sdhci_brcmstb_resume(struct device *dev)
 	ret = sdhci_pltfm_resume(dev);
 	if (!ret && priv->base_freq_hz) {
 		ret = clk_prepare_enable(priv->base_clk);
-		if (!ret)
+		/*
+		 * Note: using clk_get_rate() below as clk_get_rate()
+		 * honors CLK_GET_RATE_NOCACHE attribute, but clk_set_rate()
+		 * may do implicit get_rate() calls that do not honor
+		 * CLK_GET_RATE_NOCACHE.
+		 */
+		if (!ret &&
+		    (clk_get_rate(priv->base_clk) != priv->base_freq_hz))
 			ret = clk_set_rate(priv->base_clk, priv->base_freq_hz);
 	}
 
-- 
2.17.1


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             reply	other threads:[~2022-07-14 17:42 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-14 17:41 Kamal Dasu [this message]
2022-07-14 17:41 ` [PATCH] mmc: sdhci-brcmstb: use clk_get_rate(base_clk) in PM resume Kamal Dasu
2022-07-14 20:43 ` Florian Fainelli
2022-07-14 20:43   ` Florian Fainelli
2022-07-18 11:38 ` Ulf Hansson
2022-07-18 11:38   ` Ulf Hansson

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