Thread (269 messages) 269 messages, 1 author, 2016-01-27
STALE3820d

[PATCH 4.2.y-ckt 046/268] mmc: sdhci-pci: Do not default to 33 Ohm driver strength for Intel SPT

From: Kamal Mostafa <hidden>
Date: 2016-01-27 21:53:08
Also in: lkml
Subsystem: multimedia card (mmc), secure digital (sd) and sdio subsystem, secure digital host controller interface (sdhci) driver, the rest · Maintainers: Ulf Hansson, Adrian Hunter, Linus Torvalds

4.2.8-ckt3 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

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 <redacted>
Signed-off-by: Kamal Mostafa <redacted>
---
 drivers/mmc/host/sdhci-pci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
index b3b0a3e..5d2e222 100644
--- a/drivers/mmc/host/sdhci-pci.c
+++ b/drivers/mmc/host/sdhci-pci.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 */
-- 
1.9.1
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help