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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 [email protected] 1 participant 1 message Mar 1, 2016

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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 <[email protected]> know about it.

Quoted 1 line

From 1ca896856281d3f1ad4f6f7d4e32e2943452de23 Mon Sep 17 00:00:00 2001

From: Adrian Hunter <[email protected]>
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 <[email protected]>

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.

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