Patch "mmc: sdhci: Fix sdhci_runtime_pm_bus_on/off()" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

mmc: sdhci: Fix sdhci_runtime_pm_bus_on/off()

to the 4.4-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-fix-sdhci_runtime_pm_bus_on-off.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Adrian Hunter <[email protected]>
Date: Thu, 26 Nov 2015 14:00:50 +0200
Subject: mmc: sdhci: Fix sdhci_runtime_pm_bus_on/off()

From: Adrian Hunter <[email protected]>

commit 5c671c410c8704800f4f1673b6f572137e7e6ddd upstream.

sdhci has a legacy facility to prevent runtime suspend if the bus power is on. This is needed in cases where the power to the card is dependent on the bus power. It is controlled by a pair of functions: sdhci_runtime_pm_bus_on() and sdhci_runtime_pm_bus_off(). These functions use a boolean variable 'bus_on' to ensure changes are always paired. There is an additional check for 'runtime_suspended' which is the problem. In fact, its use is ill-conceived as the only requirement for the logic is that 'on' and 'off' are paired, which is actually broken by the check, for example if the bus power is turned on during runtime resume. So remove the check.

---
 drivers/mmc/host/sdhci.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -2763,7 +2763,7 @@ static int sdhci_runtime_pm_put(struct s
 
 static void sdhci_runtime_pm_bus_on(struct sdhci_host *host)
 {
-	if (host->runtime_suspended || host->bus_on)
+	if (host->bus_on)
 		return;
 	host->bus_on = true;
 	pm_runtime_get_noresume(host->mmc->parent);

@@ -2771,7 +2771,7 @@ static void sdhci_runtime_pm_bus_on(stru
 
 static void sdhci_runtime_pm_bus_off(struct sdhci_host *host)
 {
-	if (host->runtime_suspended || !host->bus_on)
+	if (!host->bus_on)
 		return;
 	host->bus_on = false;
 	pm_runtime_put_noidle(host->mmc->parent);

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/mmc-sdhci-acpi-fix-card-detect-race-for-intel-bxt-apl.patch queue-4.4/mmc-mmc-fix-incorrect-use-of-driver-strength-switching-hs200-and-hs400.patch queue-4.4/mmc-sdhci-allow-override-of-get_cd-called-from-sdhci_request.patch queue-4.4/mmc-sdhci-pci-do-not-default-to-33-ohm-driver-strength-for-intel-spt.patch queue-4.4/mmc-sdio-fix-invalid-vdd-in-voltage-switch-power-cycle.patch queue-4.4/mmc-sdhci-fix-sdhci_runtime_pm_bus_on-off.patch queue-4.4/mmc-sdhci-allow-override-of-mmc-host-operations.patch queue-4.4/mmc-sdhci-fix-dma-descriptor-with-zero-data-length.patch queue-4.4/mmc-sdhci-pci-fix-card-detect-race-for-intel-bxt-apl.patch