This is a note to let you know that I've just added the patch titled mmc: dw_mmc: avoid write to CDTHRCTL on older versions to the 3.18-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-dw_mmc-avoid-write-to-cdthrctl-on-older-versions.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 66dfd10173159cafa9cb0d39936b8daeaab8e3e0 Mon Sep 17 00:00:00 2001 From: James Hogan <james.hogan@xxxxxxxxxx> Date: Mon, 17 Nov 2014 17:49:05 +0000 Subject: mmc: dw_mmc: avoid write to CDTHRCTL on older versions From: James Hogan <james.hogan@xxxxxxxxxx> commit 66dfd10173159cafa9cb0d39936b8daeaab8e3e0 upstream. Commit f1d2736c8156 (mmc: dw_mmc: control card read threshold) added dw_mci_ctrl_rd_thld() with an unconditional write to the CDTHRCTL register at offset 0x100. However before version 240a, the FIFO region started at 0x100, so the write messes with the FIFO and completely breaks the driver. If the version id < 240A, return early from dw_mci_ctl_rd_thld() so as not to hit this problem. Fixes: f1d2736c8156 (mmc: dw_mmc: control card read threshold) Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx> Acked-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mmc/host/dw_mmc.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -626,6 +626,13 @@ static void dw_mci_ctrl_rd_thld(struct d WARN_ON(!(data->flags & MMC_DATA_READ)); + /* + * CDTHRCTL doesn't exist prior to 240A (in fact that register offset is + * in the FIFO region, so we really shouldn't access it). + */ + if (host->verid < DW_MMC_240A) + return; + if (host->timing != MMC_TIMING_MMC_HS200 && host->timing != MMC_TIMING_UHS_SDR104) goto disable; Patches currently in stable-queue which might be from james.hogan@xxxxxxxxxx are queue-3.18/mmc-dw_mmc-avoid-write-to-cdthrctl-on-older-versions.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html