Patch "mmc: sdhci-acpi: Only powered up enabled acpi child devices" has been added to the 4.9-stable tree

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

mmc: sdhci-acpi: Only powered up enabled acpi child devices

to the 4.9-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-acpi-only-powered-up-enabled-acpi-child-devices.patch
and it can be found in the queue-4.9 subdirectory.

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

From: Hans de Goede <[email protected]>
Date: Wed, 21 Dec 2016 00:19:19 +0100
Subject: mmc: sdhci-acpi: Only powered up enabled acpi child devices

From: Hans de Goede <[email protected]>

commit e1d070c3793a2766122865a7c2142853b48808c5 upstream.

Commit e5bbf30733f9 ("mmc: sdhci-acpi: Ensure connected devices are powered when probing") introduced code to powerup any acpi child nodes listed in the dstd. But some dstd-s list all possible devices used on some board variants, while reporting if the device is actually present and enabled in the status field of the device.

So we end up calling the acpi _PS0 (power-on) method for devices which are not actually present. This does not always end well, e.g. on my cube iwork8 air tablet, this results in freezing the entire tablet as soon as the r8723bs module is loaded.

This commit fixes this by checking the child device's status.present and status.enabled bits and only call acpi_device_fix_up_power() if both are set.

---
 drivers/mmc/host/sdhci-acpi.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -394,7 +394,8 @@ static int sdhci_acpi_probe(struct platf
 	/* Power on the SDHCI controller and its children */
 	acpi_device_fix_up_power(device);
 	list_for_each_entry(child, &device->children, node)
-		acpi_device_fix_up_power(child);
+		if (child->status.present && child->status.enabled)
+			acpi_device_fix_up_power(child);
 
 	if (acpi_bus_get_status(device) || !device->status.present)
 		return -ENODEV;

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

queue-4.9/mmc-sdhci-acpi-only-powered-up-enabled-acpi-child-devices.patch