This is a note to let you know that I've just added the patch titled
mmc: sdhci-pxav3: fix unbalanced clock issues during probe
to the 3.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mmc-sdhci-pxav3-fix-unbalanced-clock-issues-during-probe.patch
and it can be found in the queue-3.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 62cf983ad84275f8580c807e5e596216c46773cf Mon Sep 17 00:00:00 2001
From: Jisheng Zhang <jszhang@xxxxxxxxxxx>
Date: Sun, 4 Jan 2015 23:15:47 +0800
Subject: mmc: sdhci-pxav3: fix unbalanced clock issues during probe
From: Jisheng Zhang <jszhang@xxxxxxxxxxx>
commit 62cf983ad84275f8580c807e5e596216c46773cf upstream.
Commit 0dcaa2499b7d ("sdhci-pxav3: Fix runtime PM initialization") tries
to fix one hang issue caused by calling sdhci_add_host() on a suspended
device. The fix enables the clock twice, once by clk_prepare_enable() and
another by pm_runtime_get_sync(), meaning that the clock will never be
gated at runtime PM suspend. I observed the power consumption regression on
Marvell BG2Q SoCs.
In fact, the fix is not correct. There still be a very small window
during which a runtime suspend might somehow occur after pm_runtime_enable()
but before pm_runtime_get_sync().
This patch fixes all of the two problems by just incrementing the usage
counter before pm_runtime_enable(). It also adjust the order of disabling
runtime pm and storing the usage count in the error path to handle clock
gating properly.
Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci-pxav3.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/drivers/mmc/host/sdhci-pxav3.c
+++ b/drivers/mmc/host/sdhci-pxav3.c
@@ -365,10 +365,11 @@ static int sdhci_pxav3_probe(struct plat
}
}
- pm_runtime_enable(&pdev->dev);
- pm_runtime_get_sync(&pdev->dev);
+ pm_runtime_get_noresume(&pdev->dev);
+ pm_runtime_set_active(&pdev->dev);
pm_runtime_set_autosuspend_delay(&pdev->dev, PXAV3_RPM_DELAY_MS);
pm_runtime_use_autosuspend(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
pm_suspend_ignore_children(&pdev->dev, 1);
ret = sdhci_add_host(host);
@@ -391,8 +392,8 @@ static int sdhci_pxav3_probe(struct plat
return 0;
err_add_host:
- pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
+ pm_runtime_put_noidle(&pdev->dev);
err_of_parse:
err_cd_req:
err_mbus_win:
Patches currently in stable-queue which might be from jszhang@xxxxxxxxxxx are
queue-3.19/mmc-sdhci-pxav3-fix-race-between-runtime-pm-and-irq.patch
queue-3.19/mmc-sdhci-pxav3-fix-setting-of-pdata-clk_delay_cycles.patch
queue-3.19/mmc-sdhci-pxav3-fix-unbalanced-clock-issues-during-probe.patch
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