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

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>
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index cf7ad45..08f4a9f 100644 (file)
--- 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 */