mmc: mmc: do not use CMD13 to get status after speed mode switch
Per JEDEC spec, it is not recommended to use CMD13 to get card status
after speed mode switch. below are two reason about this:
1. CMD13 cannot be guaranteed due to the asynchronous operation.
Therefore it is not recommended to use CMD13 to check busy completion
of the timing change indication.
2. After switch to HS200, CMD13 will get response of 0x800, and even the
busy signal gets de-asserted, the response of CMD13 is aslo 0x800.
Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 97a664f..490229e 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -965,6 +965,19 @@
return err;
}
+/* Caller must hold re-tuning */
+static int mmc_switch_status(struct mmc_card *card)
+{
+ u32 status;
+ int err;
+
+ err = mmc_send_status(card, &status);
+ if (err)
+ return err;
+
+ return mmc_switch_status_error(card->host, status);
+}
+
/*
* Switch to the high-speed mode
*/
@@ -975,9 +988,11 @@
err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_HS_TIMING, EXT_CSD_TIMING_HS,
card->ext_csd.generic_cmd6_time,
- true, true, true);
- if (!err)
+ true, false, true);
+ if (!err) {
mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
+ err = mmc_switch_status(card);
+ }
return err;
}
@@ -1053,23 +1068,9 @@
return err;
}
-/* Caller must hold re-tuning */
-static int mmc_switch_status(struct mmc_card *card)
-{
- u32 status;
- int err;
-
- err = mmc_send_status(card, &status);
- if (err)
- return err;
-
- return mmc_switch_status_error(card->host, status);
-}
-
static int mmc_select_hs400(struct mmc_card *card)
{
struct mmc_host *host = card->host;
- bool send_status = true;
unsigned int max_dtr;
int err = 0;
u8 val;
@@ -1081,9 +1082,6 @@
host->ios.bus_width == MMC_BUS_WIDTH_8))
return 0;
- if (host->caps & MMC_CAP_WAIT_WHILE_BUSY)
- send_status = false;
-
/* Reduce frequency to HS frequency */
max_dtr = card->ext_csd.hs_max_dtr;
mmc_set_clock(host, max_dtr);
@@ -1093,7 +1091,7 @@
err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_HS_TIMING, val,
card->ext_csd.generic_cmd6_time,
- true, send_status, true);
+ true, false, true);
if (err) {
pr_err("%s: switch to high-speed from hs200 failed, err:%d\n",
mmc_hostname(host), err);
@@ -1103,11 +1101,9 @@
/* Set host controller to HS timing */
mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
- if (!send_status) {
- err = mmc_switch_status(card);
- if (err)
- goto out_err;
- }
+ err = mmc_switch_status(card);
+ if (err)
+ goto out_err;
/* Switch card to DDR */
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
@@ -1126,7 +1122,7 @@
err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_HS_TIMING, val,
card->ext_csd.generic_cmd6_time,
- true, send_status, true);
+ true, false, true);
if (err) {
pr_err("%s: switch to hs400 failed, err:%d\n",
mmc_hostname(host), err);
@@ -1137,11 +1133,9 @@
mmc_set_timing(host, MMC_TIMING_MMC_HS400);
mmc_set_bus_speed(card);
- if (!send_status) {
- err = mmc_switch_status(card);
- if (err)
- goto out_err;
- }
+ err = mmc_switch_status(card);
+ if (err)
+ goto out_err;
return 0;
@@ -1159,14 +1153,10 @@
int mmc_hs400_to_hs200(struct mmc_card *card)
{
struct mmc_host *host = card->host;
- bool send_status = true;
unsigned int max_dtr;
int err;
u8 val;
- if (host->caps & MMC_CAP_WAIT_WHILE_BUSY)
- send_status = false;
-
/* Reduce frequency to HS */
max_dtr = card->ext_csd.hs_max_dtr;
mmc_set_clock(host, max_dtr);
@@ -1175,49 +1165,43 @@
val = EXT_CSD_TIMING_HS;
err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING,
val, card->ext_csd.generic_cmd6_time,
- true, send_status, true);
+ true, false, true);
if (err)
goto out_err;
mmc_set_timing(host, MMC_TIMING_MMC_DDR52);
- if (!send_status) {
- err = mmc_switch_status(card);
- if (err)
- goto out_err;
- }
+ err = mmc_switch_status(card);
+ if (err)
+ goto out_err;
/* Switch HS DDR to HS */
err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BUS_WIDTH,
EXT_CSD_BUS_WIDTH_8, card->ext_csd.generic_cmd6_time,
- true, send_status, true);
+ true, false, true);
if (err)
goto out_err;
mmc_set_timing(host, MMC_TIMING_MMC_HS);
- if (!send_status) {
- err = mmc_switch_status(card);
- if (err)
- goto out_err;
- }
+ err = mmc_switch_status(card);
+ if (err)
+ goto out_err;
/* Switch HS to HS200 */
val = EXT_CSD_TIMING_HS200 |
card->drive_strength << EXT_CSD_DRV_STR_SHIFT;
err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING,
- val, card->ext_csd.generic_cmd6_time, true,
- send_status, true);
+ val, card->ext_csd.generic_cmd6_time,
+ true, false, true);
if (err)
goto out_err;
mmc_set_timing(host, MMC_TIMING_MMC_HS200);
- if (!send_status) {
- err = mmc_switch_status(card);
- if (err)
- goto out_err;
- }
+ err = mmc_switch_status(card);
+ if (err)
+ goto out_err;
mmc_set_bus_speed(card);
@@ -1328,7 +1312,6 @@
static int mmc_select_hs200(struct mmc_card *card)
{
struct mmc_host *host = card->host;
- bool send_status = true;
unsigned int old_timing, old_signal_voltage;
int err = -EINVAL;
u8 val;
@@ -1346,9 +1329,6 @@
mmc_select_driver_type(card);
- if (host->caps & MMC_CAP_WAIT_WHILE_BUSY)
- send_status = false;
-
/*
* Set the bus width(4 or 8) with host's support and
* switch to HS200 mode if bus width is set successfully.
@@ -1360,20 +1340,19 @@
err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_HS_TIMING, val,
card->ext_csd.generic_cmd6_time,
- true, send_status, true);
+ true, false, true);
if (err)
goto err;
old_timing = host->ios.timing;
mmc_set_timing(host, MMC_TIMING_MMC_HS200);
- if (!send_status) {
- err = mmc_switch_status(card);
- /*
- * mmc_select_timing() assumes timing has not changed if
- * it is a switch error.
- */
- if (err == -EBADMSG)
- mmc_set_timing(host, old_timing);
- }
+
+ err = mmc_switch_status(card);
+ /*
+ * mmc_select_timing() assumes timing has not changed if
+ * it is a switch error.
+ */
+ if (err == -EBADMSG)
+ mmc_set_timing(host, old_timing);
}
err:
if (err) {
