2.6.20 mmc: problem with highspeed SD card

["Eugene Ilkov" <e.ilkov@gmail.com>]

I have I/O errors with Transcend SD highspeed card 2GB/150x when it's
mounted in r/w mode (cardreader on sharp sl-c1000)
It works well  if I reverse mmcv4 patch commited to 2.6.19-git2
(http://lkml.org/lkml/2006/10/4/27)
I'm not experienced in mmc, but I figured out that problem is
somewhere in mmc_read_switch_caps() and when i change cmd.arg value
from 0x80FFFFF1 to 0x00FFFFF1 it works fine too
What argument should have SD_SWITCH opcode?


--- linux-2.6.20/drivers/mmc/mmc.c      2007-02-14 04:13:23.644408219 +0300
+++ linux-2.6.20.g/drivers/mmc/mmc.c    2007-02-14 04:19:09.642624022 +0300
@@ -1225,7 +1225,7 @@
                memset(&cmd, 0, sizeof(struct mmc_command));

                cmd.opcode = SD_SWITCH;
-               cmd.arg = 0x80FFFFF1;
+               cmd.arg = 0x00FFFFF1;
                cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;

                memset(&data, 0, sizeof(struct mmc_data));