[PATCH 8/32] mmc: check status after MMC SWITCH command

Adrian Hunter
2009-07-10T12:40:50Z

>From cda3074c6233408ec29365c5e63b80567bff8c5c Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter@nokia.com>
Date: Wed, 3 Jun 2009 12:22:29 +0300
Subject: [PATCH] mmc: check status after MMC SWITCH command

According to the standard, the SWITCH command should
be followed by a SEND_STATUS command to check for
errors.

Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
---
drivers/mmc/core/mmc.c | 24 ++++++++++++++++++------
drivers/mmc/core/mmc_ops.c | 23 +++++++++++++++++++++++
include/linux/mmc/mmc.h | 1 +
3 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 8e2e3d2..f87cc0b 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -416,12 +416,17 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
(host->caps & MMC_CAP_MMC_HIGHSPEED)) {
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_HS_TIMING, 1);
- if (err)
+ if (err && err != -EBADMSG)
goto free_card;

- mmc_card_set_highspeed(card);
-
- mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
+ if (err) {
+ printk(KERN_WARNING "%s: switch to highspeed failed\n",
+ mmc_hostname(card->host));
+ err = 0;
+ } else {
+ mmc_card_set_highspeed(card);
+ mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
+ }
}

/*
@@ -456,10 +461,17 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_BUS_WIDTH, ext_csd_bit);

- if (err)
+ if (err && err != -EBADMSG)
goto free_card;

- mmc_set_bus_width(card->host, bus_width);
+ if (err) {
+ printk(KERN_WARNING "%s: switch to bus width %d "
+ "failed\n", mmc_hostname(card->host),
+ 1 << bus_width);
+ err = 0;
+ } else {
+ mmc_set_bus_width(card->host, bus_width);
+ }
}

if (!oldcard)
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 355c604..d2cb5c6 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -390,6 +390,7 @@ int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value)
{
int err;
struct mmc_command cmd;
+ u32 status;

BUG_ON(!card);
BUG_ON(!card->host);
@@ -407,6 +408,28 @@ int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value)
if (err)
return err;

+ /* Must check status to be sure of no errors */
+ do {
+ err = mmc_send_status(card, &status);
+ if (err)
+ return err;
+ if (card->host->caps & MMC_CAP_WAIT_WHILE_BUSY)
+ break;
+ if (mmc_host_is_spi(card->host))
+ break;
+ } while (R1_CURRENT_STATE(status) == 7);
+
+ if (mmc_host_is_spi(card->host)) {
+ if (status & R1_SPI_ILLEGAL_COMMAND)
+ return -EBADMSG;
+ } else {
+ if (status & 0xFDFFA000)
+ printk(KERN_WARNING "%s: unexpected status %#x after "
+ "switch", mmc_hostname(card->host), status);
+ if (status & R1_SWITCH_ERROR)
+ return -EBADMSG;
+ }
+
return 0;
}

diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index b2b4095..c02c8db 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -128,6 +128,7 @@
#define R1_STATUS(x) (x & 0xFFFFE000)
#define R1_CURRENT_STATE(x) ((x & 0x00001E00) >> 9) /* sx, b (4 bits) */
#define R1_READY_FOR_DATA (1 << 8) /* sx, a */
+#define R1_SWITCH_ERROR (1 << 7) /* sx, c */
#define R1_APP_CMD (1 << 5) /* sr, c */

/*
--
1.5.6.3