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authorNicolas Pitre <nico@cam.org>2009-05-14 21:28:05 -0400
committerPierre Ossman <pierre@ossman.eu>2009-06-03 21:50:33 +0200
commit9ca6944cbfad11f2368cf10292e7f3eb036386c2 (patch)
tree34ccddcff0f07166da9d053d5ee02181797a27d3 /drivers
parente749c6f21fd7dc618f61dd178b4ee739c3cb1c31 (diff)
downloadop-kernel-dev-9ca6944cbfad11f2368cf10292e7f3eb036386c2.zip
op-kernel-dev-9ca6944cbfad11f2368cf10292e7f3eb036386c2.tar.gz
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>
Diffstat (limited to 'drivers')
-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 1783043..9d3cfa9 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);
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