Patch "mmc: sdhci-pci: Do not default to 33 Ohm driver strength for Intel SPT" has been added to the 4.4-stable tree

Patch "mmc: sdhci-pci: Do not default to 33 Ohm driver strength for Intel SPT" has been added to the 4.4-stable tree

[gregkh]

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

    mmc: sdhci-pci: Do not default to 33 Ohm driver strength for Intel SPT

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-pci-do-not-default-to-33-ohm-driver-strength-for-intel-spt.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 <stable@vger.kernel.org> know about it.


>From 1ca896856281d3f1ad4f6f7d4e32e2943452de23 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter@intel.com>
Date: Thu, 26 Nov 2015 14:00:45 +0200
Subject: mmc: sdhci-pci: Do not default to 33 Ohm driver strength for Intel SPT

From: Adrian Hunter <adrian.hunter@intel.com>

commit 1ca896856281d3f1ad4f6f7d4e32e2943452de23 upstream.

In some cases, the stronger 33 Ohm driver strength must not be used
so it is not a suitable default.  Change it to the standard default
50 Ohm value.

The patch applies to v4.2+ except the file name changed.  It is
drivers/mmc/host/sdhci-pci.c prior to v.4.4.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/mmc/host/sdhci-pci-core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -277,7 +277,7 @@ static int spt_select_drive_strength(str
 	if (sdhci_pci_spt_drive_strength > 0)
 		drive_strength = sdhci_pci_spt_drive_strength & 0xf;
 	else
-		drive_strength = 1; /* 33-ohm */
+		drive_strength = 0; /* Default 50-ohm */
 
 	if ((mmc_driver_type_mask(drive_strength) & card_drv) == 0)
 		drive_strength = 0; /* Default 50-ohm */


Patches currently in stable-queue which might be from adrian.hunter@intel.com 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