提交 3373c0ae 编写于 作者: P Pierre Ossman

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: NPierre Ossman <drzeus@drzeus.cx>
上级 71651297
......@@ -15,6 +15,7 @@
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sd.h>
#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;
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册