Messages in this thread Patch in this message | | | From | Jisheng Zhang <> | Subject | [PATCH next 1/2] mmc: sdhci-pxav3: fix unbalanced clock issues during probe | Date | Sun, 4 Jan 2015 23:15:47 +0800 |
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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@marvell.com> Cc: <stable@vger.kernel.org> # v3.11+ --- drivers/mmc/host/sdhci-pxav3.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c index ca3424e..1255dd2 100644 --- a/drivers/mmc/host/sdhci-pxav3.c +++ b/drivers/mmc/host/sdhci-pxav3.c @@ -365,10 +365,11 @@ static int sdhci_pxav3_probe(struct platform_device *pdev) } } - 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 platform_device *pdev) 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: -- 2.1.4
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