From: Adrian Hunter <adrian.hunter@intel.com>
Date: Thu, 26 Nov 2015 12:00:45 +0000 (+0200)
Subject: mmc: sdhci-pci: Do not default to 33 Ohm driver strength for Intel SPT
X-Git-Tag: firefly_0821_release~176^2~475^2~285
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=4a3d7e16b0f4729151f41061f5fc9cf91279b997;p=firefly-linux-kernel-4.4.55.git

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

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>
---

diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index cf7ad458b4f4..08f4a9fe8550 100644
--- 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(struct sdhci_host *host,
 	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 */