mmc: sdhci-pxav3: fix unbalanced clock issues during probe
Commit 0dcaa249 ("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: NJisheng Zhang <jszhang@marvell.com> Cc: <stable@vger.kernel.org> # v3.11+ Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
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