From f2815f68dabbb373fd1c9f0fd4a609d486697c2b Mon Sep 17 00:00:00 2001 From: Subhash Jadavani Date: Wed, 10 Aug 2011 11:16:01 +0530 Subject: [PATCH] mmc: sd: Handle SD3.0 cards not supporting UHS-I bus speed mode Here is Essential conditions to indicate Version 3.00 Card (SD_SPEC=2 and SD_SPEC3=1) : (1) The card shall support CMD6 (2) The card shall support CMD8 (3) The card shall support CMD42 (4) User area capacity shall be up to 2GB (SDSC) or 32GB (SDHC) User area capacity shall be more than or equal to 32GB and up to 2TB (SDXC) (5) Speed Class shall be supported (SDHC or SDXC) So even if SD card doesn't support any of the newly defined UHS-I bus speed mode, it can advertise itself as SD3.0 cards as long as it supports all the essential conditions of SD3.0 cards. Given this, these type of cards should atleast run in High Speed mode @50MHZ if it supports HS. But current initialization sequence for SD3.0 cards is such that these non-UHS-I SD3.0 cards runs in Default Speed mode @25MHz. This patch makes sure that these non-UHS-I SD3.0 cards run in High Speed Mode @50MHz. Tested this patch with SanDisk Extreme SDHC 8GB Class 10 card. Reported-by: "Hiremath, Vaibhav" Signed-off-by: Subhash Jadavani Signed-off-by: Chris Ball --- drivers/mmc/core/sd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index 25b937294130..a230e7f9d77a 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -306,6 +306,9 @@ static int mmc_read_switch(struct mmc_card *card) goto out; } + if (status[13] & UHS_SDR50_BUS_SPEED) + card->sw_caps.hs_max_dtr = 50000000; + if (card->scr.sda_spec3) { card->sw_caps.sd3_bus_mode = status[13]; @@ -348,9 +351,6 @@ static int mmc_read_switch(struct mmc_card *card) } card->sw_caps.sd3_curr_limit = status[7]; - } else { - if (status[13] & 0x02) - card->sw_caps.hs_max_dtr = 50000000; } out: -- 2.39.2