This is a note to let you know that I've just added the patch titled
mmc: Prevent 1.8V switch for SD hosts that don't support UHS modes.
to the 3.0-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-prevent-1.8v-switch-for-sd-hosts-that-don-t-support-uhs-modes.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 4188bba0e9e7ba58d231b528df495666f2742b74 Mon Sep 17 00:00:00 2001
From: Al Cooper <[email protected]>
Date: Fri, 16 Mar 2012 15:54:17 -0400
Subject: mmc: Prevent 1.8V switch for SD hosts that don't support UHS modes.
From: Al Cooper <[email protected]>
commit 4188bba0e9e7ba58d231b528df495666f2742b74 upstream.
The driver should not try to switch to 1.8V when the SD 3.0 host
controller does not have any UHS capabilities bits set (SDR50, DDR50
or SDR104). See page 72 of "SD Specifications Part A2 SD Host
Controller Simplified Specification Version 3.00" under
"1.8V Signaling Enable". Instead of setting SDR12 and SDR25 in the host
capabilities data structure for all V3.0 host controllers, only set them
if SDR104, SDR50 or DDR50 is set in the host capabilities register. This
will prevent the switch to 1.8V later.
Signed-off-by: Al Cooper <[email protected]>
Acked-by: Arindam Nath <[email protected]>
Acked-by: Philip Rakity <[email protected]>
Acked-by: Girish K S <[email protected]>
Signed-off-by: Chris Ball <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/mmc/host/sdhci.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2515,8 +2515,9 @@ int sdhci_add_host(struct sdhci_host *ho
mmc_card_is_removable(mmc))
mmc->caps |= MMC_CAP_NEEDS_POLL;
- /* UHS-I mode(s) supported by the host controller. */
- if (host->version >= SDHCI_SPEC_300)
+ /* Any UHS-I mode in caps implies SDR12 and SDR25 support. */
+ if (caps[1] & (SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |
+ SDHCI_SUPPORT_DDR50))
mmc->caps |= MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25;
/* SDR104 supports also implies SDR50 support */
Patches currently in stable-queue which might be from [email protected] are
queue-3.0/mmc-prevent-1.8v-switch-for-sd-hosts-that-don-t-support-uhs-modes.patch
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