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authorNicolas Pitre <nico@cam.org>2009-05-15 03:28:05 +0200
committerPierre Ossman <pierre@ossman.eu>2009-06-03 21:50:33 +0200
commit9ca6944cbfad11f2368cf10292e7f3eb036386c2 (patch)
tree34ccddcff0f07166da9d053d5ee02181797a27d3
parentmmc/omap: Use disable_irq_nosync() from within irq handlers. (diff)
downloadlinux-9ca6944cbfad11f2368cf10292e7f3eb036386c2.tar.xz
linux-9ca6944cbfad11f2368cf10292e7f3eb036386c2.zip
mvsdio: ignore high speed timing requests from the core
Empirical evidences show that this is causing far more problems than it solves when this mode is enabled in the host hardware. Amongst those cards that are known to be non functional when this bit is set are: A-Data "Speedy" 2GB SD card Kodak 512MB SD card Ativa 1GB MicroSD card Marvell 8688 (WIFI/Bluetooth) SDIO card Since those cards do work on other host controllers which do honnor the hs timing, the issue must be with this particular host hardware. Signed-off-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Pierre Ossman <pierre@ossman.eu>
-rw-r--r--drivers/mmc/host/mvsdio.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/mmc/host/mvsdio.c b/drivers/mmc/host/mvsdio.c
index 1783043a26af..9d3cfa9909c9 100644
--- a/drivers/mmc/host/mvsdio.c
+++ b/drivers/mmc/host/mvsdio.c
@@ -620,9 +620,18 @@ static void mvsd_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
if (ios->bus_width == MMC_BUS_WIDTH_4)
ctrl_reg |= MVSD_HOST_CTRL_DATA_WIDTH_4_BITS;
+ /*
+ * The HI_SPEED_EN bit is causing trouble with many (but not all)
+ * high speed SD, SDHC and SDIO cards. Not enabling that bit
+ * makes all cards work. So let's just ignore that bit for now
+ * and revisit this issue if problems for not enabling this bit
+ * are ever reported.
+ */
+#if 0
if (ios->timing == MMC_TIMING_MMC_HS ||
ios->timing == MMC_TIMING_SD_HS)
ctrl_reg |= MVSD_HOST_CTRL_HI_SPEED_EN;
+#endif
host->ctrl = ctrl_reg;
mvsd_write(MVSD_HOST_CTRL, ctrl_reg);