From 3373c0ae6a51085b10a95fd9d2214a9995ef7563 Mon Sep 17 00:00:00 2001 From: Pierre Ossman Date: Thu, 31 May 2007 22:25:11 +0200 Subject: [PATCH] mmc: don't call switch on old cards Make sure we don't call the switch function on cards too old to support it. They should just ignore it, but some have been reported to lock up instead. Signed-off-by: Pierre Ossman --- drivers/mmc/core/sd.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index 5afac2081185..41bfb5dfe6ff 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -15,6 +15,7 @@ #include #include #include +#include #include "core.h" #include "sysfs.h" @@ -192,6 +193,16 @@ static int mmc_read_switch(struct mmc_card *card) int err; u8 *status; + if (card->scr.sda_vsn < SCR_SPEC_VER_1) + return MMC_ERR_NONE; + + if (!(card->csd.cmdclass & CCC_SWITCH)) { + printk(KERN_WARNING "%s: card lacks mandatory switch " + "function, performance might suffer.\n", + mmc_hostname(card->host)); + return MMC_ERR_NONE; + } + err = MMC_ERR_FAILED; status = kmalloc(64, GFP_KERNEL); @@ -204,10 +215,9 @@ static int mmc_read_switch(struct mmc_card *card) err = mmc_sd_switch(card, 0, 0, 1, status); if (err != MMC_ERR_NONE) { - /* - * Card not supporting high-speed will ignore the - * command. - */ + printk(KERN_WARNING "%s: problem reading switch " + "capabilities, performance might suffer.\n", + mmc_hostname(card->host)); err = MMC_ERR_NONE; goto out; } @@ -229,6 +239,12 @@ static int mmc_switch_hs(struct mmc_card *card) int err; u8 *status; + if (card->scr.sda_vsn < SCR_SPEC_VER_1) + return MMC_ERR_NONE; + + if (!(card->csd.cmdclass & CCC_SWITCH)) + return MMC_ERR_NONE; + if (!(card->host->caps & MMC_CAP_SD_HIGHSPEED)) return MMC_ERR_NONE; -- 2.30.2