Hi Bing, The function mmc_host_uhs() will return false and never set bit[24] (S18R) for SDIO 2.0 cards. Thanks, Jackey -----Original Message----- From: linux-mmc-owner@xxxxxxxxxxxxxxx [mailto:linux-mmc-owner@xxxxxxxxxxxxxxx] On Behalf Of Bing Zhao Sent: Wednesday, December 05, 2012 5:14 AM To: Subhash Jadavani; linux-mmc@xxxxxxxxxxxxxxx Cc: linux-arm-msm@xxxxxxxxxxxxxxx; Sujit Reddy Thumma Subject: RE: [PATCH v1 2/3] mmc: sdio: Fix SDIO 3.0 UHS-I initialization sequence Hi, > From: Sujit Reddy Thumma <sthumma@xxxxxxxxxxxxxx> > > According to UHS-I initialization sequence for SDIO 3.0 cards, the > host must set bit[24] (S18R) of OCR register during OCR handshake to > know whether the SDIO card is capable of doing 1.8V I/O. In SDIO 2.0 spec, bit[24] is reserved, "shall be set to 0". Setting it to 1 might cause side effect to 2.0 cards. Perhaps using a quirk for S18R is more suitable for all combinations. Regards, Bing > > Signed-off-by: Sujit Reddy Thumma <sthumma@xxxxxxxxxxxxxx> > Signed-off-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx> > --- > drivers/mmc/core/sdio.c | 22 +++++++++++----------- > include/linux/mmc/host.h | 8 ++++++++ > 2 files changed, 19 insertions(+), 11 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
