| Message ID | 1462344872-6448-1-git-send-email-chaotian.jing@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
+ linux-rockchip I just hacked my local branch to fix the issues found on rockchip platform. The reaseon is that mmc core fail to get status after switching from hs200 to hs. So I disabled sending status for it just like what Chaotian does here. But I didn't deeply dig out the root cause but I agree with Chaotian's opinion. FYI: My emmc deivce is KLMA62WEPD-B031. [ 1.526008] sdhci: Secure Digital Host Controller Interface driver [ 1.526558] sdhci: Copyright(c) Pierre Ossman [ 1.527899] sdhci-pltfm: SDHCI platform and OF driver helper [ 1.529967] sdhci-arasan fe330000.sdhci: No vmmc regulator found [ 1.530501] sdhci-arasan fe330000.sdhci: No vqmmc regulator found [ 1.568710] mmc0: SDHCI controller on fe330000.sdhci [fe330000.sdhci] using ADMA [ 1.627552] mmc0: switch to high-speed from hs200 failed, err:-84 [ 1.628108] mmc0: error -84 whilst initialising MMC card ? 2016/5/4 14:54, Chaotian Jing ??: > 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. > > this patch drops CMD13 when doing speed mode switch, if host do not > support MMC_CAP_WAIT_WHILE_BUSY and there is no ops->card_busy(), > then the only way is to wait a fixed timeout. > > Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com> > --- > drivers/mmc/core/mmc.c | 82 ++++++++++++++++---------------------------- > drivers/mmc/core/mmc_ops.c | 25 +++++++++----- > 2 files changed, 45 insertions(+), 62 deletions(-) > > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c > index 4dbe3df..03ee7a4 100644 > --- a/drivers/mmc/core/mmc.c > +++ b/drivers/mmc/core/mmc.c > @@ -962,7 +962,7 @@ static int mmc_select_hs(struct mmc_card *card) > 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); > + true, false, true); > if (!err) > mmc_set_timing(card->host, MMC_TIMING_MMC_HS); > > @@ -1056,7 +1056,6 @@ static int mmc_switch_status(struct mmc_card *card) > 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; > @@ -1068,9 +1067,6 @@ static int mmc_select_hs400(struct mmc_card *card) > 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); > @@ -1080,7 +1076,7 @@ static int mmc_select_hs400(struct mmc_card *card) > 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); > @@ -1090,11 +1086,9 @@ static int mmc_select_hs400(struct mmc_card *card) > /* 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, > @@ -1113,7 +1107,7 @@ static int mmc_select_hs400(struct mmc_card *card) > 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); > @@ -1124,11 +1118,9 @@ static int mmc_select_hs400(struct mmc_card *card) > 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; > > @@ -1146,14 +1138,10 @@ int mmc_hs200_to_hs400(struct mmc_card *card) > 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); > @@ -1162,49 +1150,43 @@ int mmc_hs400_to_hs200(struct mmc_card *card) > 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); > + 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); > > @@ -1243,7 +1225,6 @@ static void mmc_select_driver_type(struct mmc_card *card) > static int mmc_select_hs200(struct mmc_card *card) > { > struct mmc_host *host = card->host; > - bool send_status = true; > unsigned int old_timing; > int err = -EINVAL; > u8 val; > @@ -1260,9 +1241,6 @@ static int mmc_select_hs200(struct mmc_card *card) > > 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. > @@ -1274,20 +1252,18 @@ static int mmc_select_hs200(struct mmc_card *card) > 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) > diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c > index 62355bd..32de144 100644 > --- a/drivers/mmc/core/mmc_ops.c > +++ b/drivers/mmc/core/mmc_ops.c > @@ -480,6 +480,7 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, > u32 status = 0; > bool use_r1b_resp = use_busy_signal; > bool expired = false; > + bool busy = false; > > mmc_retune_hold(host); > > @@ -535,19 +536,24 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, > /* Must check status to be sure of no errors. */ > timeout = jiffies + msecs_to_jiffies(timeout_ms); > do { > + /* > + * Due to the possibility of being preempted after > + * sending the status command, check the expiration > + * time first. > + */ > + expired = time_after(jiffies, timeout); > if (send_status) { > - /* > - * Due to the possibility of being preempted after > - * sending the status command, check the expiration > - * time first. > - */ > - expired = time_after(jiffies, timeout); > err = __mmc_send_status(card, &status, ignore_crc); > if (err) > goto out; > } > if ((host->caps & MMC_CAP_WAIT_WHILE_BUSY) && use_r1b_resp) > break; > + if (host->ops->card_busy) { > + if (!host->ops->card_busy(host)) > + break; > + busy = true; > + } > if (mmc_host_is_spi(host)) > break; > > @@ -556,19 +562,20 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, > * does'nt support MMC_CAP_WAIT_WHILE_BUSY, then we can only > * rely on waiting for the stated timeout to be sufficient. > */ > - if (!send_status) { > + if (!send_status && !host->ops->card_busy) { > mmc_delay(timeout_ms); > goto out; > } > > /* Timeout if the device never leaves the program state. */ > - if (expired && R1_CURRENT_STATE(status) == R1_STATE_PRG) { > + if (expired && > + (R1_CURRENT_STATE(status) == R1_STATE_PRG || busy)) { > pr_err("%s: Card stuck in programming state! %s\n", > mmc_hostname(host), __func__); > err = -ETIMEDOUT; > goto out; > } > - } while (R1_CURRENT_STATE(status) == R1_STATE_PRG); > + } while (R1_CURRENT_STATE(status) == R1_STATE_PRG || busy); > > err = mmc_switch_status_error(host, status); > out: >
On 04/05/16 09:54, Chaotian Jing wrote: > 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. > > this patch drops CMD13 when doing speed mode switch, if host do not > support MMC_CAP_WAIT_WHILE_BUSY and there is no ops->card_busy(), > then the only way is to wait a fixed timeout. This looks like it should be 3 patches: 1. Change __mmc_switch 2. Change HS200 and HS400 selection 3. Change HS selection However there is another problem: card_busy is not the same as busy signal - see below. So that needs to be sorted out first. > > Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com> > --- > drivers/mmc/core/mmc.c | 82 ++++++++++++++++---------------------------- > drivers/mmc/core/mmc_ops.c | 25 +++++++++----- > 2 files changed, 45 insertions(+), 62 deletions(-) > > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c > index 4dbe3df..03ee7a4 100644 > --- a/drivers/mmc/core/mmc.c > +++ b/drivers/mmc/core/mmc.c > @@ -962,7 +962,7 @@ static int mmc_select_hs(struct mmc_card *card) > 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); > + true, false, true); If you are going to do that, then you still need to do mmc_switch_status(card). But we have done CMD13 polling for HS for a long time, so this should be a separate patch and separately justified. Maybe we should still poll if !(host->caps & MMC_CAP_WAIT_WHILE_BUSY) && !host->ops->card_busy. > if (!err) > mmc_set_timing(card->host, MMC_TIMING_MMC_HS); > > @@ -1056,7 +1056,6 @@ static int mmc_switch_status(struct mmc_card *card) > 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; > @@ -1068,9 +1067,6 @@ static int mmc_select_hs400(struct mmc_card *card) > 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); > @@ -1080,7 +1076,7 @@ static int mmc_select_hs400(struct mmc_card *card) > 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); > @@ -1090,11 +1086,9 @@ static int mmc_select_hs400(struct mmc_card *card) > /* 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, > @@ -1113,7 +1107,7 @@ static int mmc_select_hs400(struct mmc_card *card) > 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); > @@ -1124,11 +1118,9 @@ static int mmc_select_hs400(struct mmc_card *card) > 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; > > @@ -1146,14 +1138,10 @@ int mmc_hs200_to_hs400(struct mmc_card *card) > 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); > @@ -1162,49 +1150,43 @@ int mmc_hs400_to_hs200(struct mmc_card *card) > 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); > + 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); > > @@ -1243,7 +1225,6 @@ static void mmc_select_driver_type(struct mmc_card *card) > static int mmc_select_hs200(struct mmc_card *card) > { > struct mmc_host *host = card->host; > - bool send_status = true; > unsigned int old_timing; > int err = -EINVAL; > u8 val; > @@ -1260,9 +1241,6 @@ static int mmc_select_hs200(struct mmc_card *card) > > 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. > @@ -1274,20 +1252,18 @@ static int mmc_select_hs200(struct mmc_card *card) > 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) > diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c > index 62355bd..32de144 100644 > --- a/drivers/mmc/core/mmc_ops.c > +++ b/drivers/mmc/core/mmc_ops.c > @@ -480,6 +480,7 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, > u32 status = 0; > bool use_r1b_resp = use_busy_signal; > bool expired = false; > + bool busy = false; > > mmc_retune_hold(host); > > @@ -535,19 +536,24 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, > /* Must check status to be sure of no errors. */ > timeout = jiffies + msecs_to_jiffies(timeout_ms); > do { > + /* > + * Due to the possibility of being preempted after > + * sending the status command, check the expiration > + * time first. > + */ > + expired = time_after(jiffies, timeout); > if (send_status) { > - /* > - * Due to the possibility of being preempted after > - * sending the status command, check the expiration > - * time first. > - */ > - expired = time_after(jiffies, timeout); > err = __mmc_send_status(card, &status, ignore_crc); > if (err) > goto out; > } > if ((host->caps & MMC_CAP_WAIT_WHILE_BUSY) && use_r1b_resp) > break; > + if (host->ops->card_busy) { card_busy is a problem because it is designed for SD voltage switch which checks DAT[3:0] whereas the busy signal is only DAT0. > + if (!host->ops->card_busy(host)) > + break; > + busy = true; > + } > if (mmc_host_is_spi(host)) > break; I would tend to put all the changes together here after the mmc_host_is_spi() check i.e. if (host->ops->card_busy) { expired = time_after(jiffies, timeout); if (!host->ops->card_busy(host)) break; if (!expired) { cond_resched(); continue; } pr_err("%s: Card stuck in busy state! %s\n", mmc_hostname(host), __func__); err = -ETIMEDOUT; goto out; } Also I think the changes to __mmc_switch() should be a separate patch. However you can't go forward with this until you sort out what card_busy means. > > @@ -556,19 +562,20 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, > * does'nt support MMC_CAP_WAIT_WHILE_BUSY, then we can only > * rely on waiting for the stated timeout to be sufficient. > */ > - if (!send_status) { > + if (!send_status && !host->ops->card_busy) { > mmc_delay(timeout_ms); > goto out; > } > > /* Timeout if the device never leaves the program state. */ > - if (expired && R1_CURRENT_STATE(status) == R1_STATE_PRG) { > + if (expired && > + (R1_CURRENT_STATE(status) == R1_STATE_PRG || busy)) { > pr_err("%s: Card stuck in programming state! %s\n", > mmc_hostname(host), __func__); > err = -ETIMEDOUT; > goto out; > } > - } while (R1_CURRENT_STATE(status) == R1_STATE_PRG); > + } while (R1_CURRENT_STATE(status) == R1_STATE_PRG || busy); > > err = mmc_switch_status_error(host, status); > out: >
On Wed, 2016-05-11 at 10:50 +0300, Adrian Hunter wrote: > On 04/05/16 09:54, Chaotian Jing wrote: > > 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. > > > > this patch drops CMD13 when doing speed mode switch, if host do not > > support MMC_CAP_WAIT_WHILE_BUSY and there is no ops->card_busy(), > > then the only way is to wait a fixed timeout. > > This looks like it should be 3 patches: > 1. Change __mmc_switch > 2. Change HS200 and HS400 selection > 3. Change HS selection > > However there is another problem: card_busy is not the same as busy signal - > see below. So that needs to be sorted out first. > We should make that card_busy() is the same with busy signal asserted. as you know, if card was not in busy state, all data pins should be high level as it is pull-up by default. so that's no conflict to check card busy signal by DAT0 or DAT0 ~ DAT3. And, if someone thinks that its card_busy() is only used for SD card, then its MMC host driver should not provide ops->card_busy(). > > > > Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com> > > --- > > drivers/mmc/core/mmc.c | 82 ++++++++++++++++---------------------------- > > drivers/mmc/core/mmc_ops.c | 25 +++++++++----- > > 2 files changed, 45 insertions(+), 62 deletions(-) > > > > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c > > index 4dbe3df..03ee7a4 100644 > > --- a/drivers/mmc/core/mmc.c > > +++ b/drivers/mmc/core/mmc.c > > @@ -962,7 +962,7 @@ static int mmc_select_hs(struct mmc_card *card) > > 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); > > + true, false, true); > > If you are going to do that, then you still need to do mmc_switch_status(card). > > But we have done CMD13 polling for HS for a long time, so this should be a > separate patch and separately justified. Maybe we should still poll if > !(host->caps & MMC_CAP_WAIT_WHILE_BUSY) && !host->ops->card_busy. > > > if (!err) > > mmc_set_timing(card->host, MMC_TIMING_MMC_HS); > > > > @@ -1056,7 +1056,6 @@ static int mmc_switch_status(struct mmc_card *card) > > 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; > > @@ -1068,9 +1067,6 @@ static int mmc_select_hs400(struct mmc_card *card) > > 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); > > @@ -1080,7 +1076,7 @@ static int mmc_select_hs400(struct mmc_card *card) > > 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); > > @@ -1090,11 +1086,9 @@ static int mmc_select_hs400(struct mmc_card *card) > > /* 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, > > @@ -1113,7 +1107,7 @@ static int mmc_select_hs400(struct mmc_card *card) > > 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); > > @@ -1124,11 +1118,9 @@ static int mmc_select_hs400(struct mmc_card *card) > > 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; > > > > @@ -1146,14 +1138,10 @@ int mmc_hs200_to_hs400(struct mmc_card *card) > > 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); > > @@ -1162,49 +1150,43 @@ int mmc_hs400_to_hs200(struct mmc_card *card) > > 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); > > + 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); > > > > @@ -1243,7 +1225,6 @@ static void mmc_select_driver_type(struct mmc_card *card) > > static int mmc_select_hs200(struct mmc_card *card) > > { > > struct mmc_host *host = card->host; > > - bool send_status = true; > > unsigned int old_timing; > > int err = -EINVAL; > > u8 val; > > @@ -1260,9 +1241,6 @@ static int mmc_select_hs200(struct mmc_card *card) > > > > 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. > > @@ -1274,20 +1252,18 @@ static int mmc_select_hs200(struct mmc_card *card) > > 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) > > diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c > > index 62355bd..32de144 100644 > > --- a/drivers/mmc/core/mmc_ops.c > > +++ b/drivers/mmc/core/mmc_ops.c > > @@ -480,6 +480,7 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, > > u32 status = 0; > > bool use_r1b_resp = use_busy_signal; > > bool expired = false; > > + bool busy = false; > > > > mmc_retune_hold(host); > > > > @@ -535,19 +536,24 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, > > /* Must check status to be sure of no errors. */ > > timeout = jiffies + msecs_to_jiffies(timeout_ms); > > do { > > + /* > > + * Due to the possibility of being preempted after > > + * sending the status command, check the expiration > > + * time first. > > + */ > > + expired = time_after(jiffies, timeout); > > if (send_status) { > > - /* > > - * Due to the possibility of being preempted after > > - * sending the status command, check the expiration > > - * time first. > > - */ > > - expired = time_after(jiffies, timeout); > > err = __mmc_send_status(card, &status, ignore_crc); > > if (err) > > goto out; > > } > > if ((host->caps & MMC_CAP_WAIT_WHILE_BUSY) && use_r1b_resp) > > break; > > + if (host->ops->card_busy) { > > card_busy is a problem because it is designed for SD voltage switch which > checks DAT[3:0] whereas the busy signal is only DAT0. > > > + if (!host->ops->card_busy(host)) > > + break; > > + busy = true; > > + } > > if (mmc_host_is_spi(host)) > > break; > > I would tend to put all the changes together here after the > mmc_host_is_spi() check i.e. > > if (host->ops->card_busy) { > expired = time_after(jiffies, timeout); > if (!host->ops->card_busy(host)) > break; > if (!expired) { > cond_resched(); > continue; > } > pr_err("%s: Card stuck in busy state! %s\n", > mmc_hostname(host), __func__); > err = -ETIMEDOUT; > goto out; > } > > Also I think the changes to __mmc_switch() should be a separate patch. > However you can't go forward with this until you sort out what card_busy means. > > > > > @@ -556,19 +562,20 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, > > * does'nt support MMC_CAP_WAIT_WHILE_BUSY, then we can only > > * rely on waiting for the stated timeout to be sufficient. > > */ > > - if (!send_status) { > > + if (!send_status && !host->ops->card_busy) { > > mmc_delay(timeout_ms); > > goto out; > > } > > > > /* Timeout if the device never leaves the program state. */ > > - if (expired && R1_CURRENT_STATE(status) == R1_STATE_PRG) { > > + if (expired && > > + (R1_CURRENT_STATE(status) == R1_STATE_PRG || busy)) { > > pr_err("%s: Card stuck in programming state! %s\n", > > mmc_hostname(host), __func__); > > err = -ETIMEDOUT; > > goto out; > > } > > - } while (R1_CURRENT_STATE(status) == R1_STATE_PRG); > > + } while (R1_CURRENT_STATE(status) == R1_STATE_PRG || busy); > > > > err = mmc_switch_status_error(host, status); > > out: > > >
On 12/05/16 10:00, Chaotian Jing wrote: > On Wed, 2016-05-11 at 10:50 +0300, Adrian Hunter wrote: >> On 04/05/16 09:54, Chaotian Jing wrote: >>> 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. >>> >>> this patch drops CMD13 when doing speed mode switch, if host do not >>> support MMC_CAP_WAIT_WHILE_BUSY and there is no ops->card_busy(), >>> then the only way is to wait a fixed timeout. >> >> This looks like it should be 3 patches: >> 1. Change __mmc_switch >> 2. Change HS200 and HS400 selection >> 3. Change HS selection >> >> However there is another problem: card_busy is not the same as busy signal - >> see below. So that needs to be sorted out first. >> > We should make that card_busy() is the same with busy signal asserted. > as you know, if card was not in busy state, all data pins should be high > level as it is pull-up by default. so that's no conflict to check card > busy signal by DAT0 or DAT0 ~ DAT3. Potentially SDIO uses DAT1 for card interrupt, so that is a conflict right there. Also SDHCI does it backwards (don't ask me why) and considers 0000 to be busy, so there's another conflict. Some of the language in the SD and SDHCI specifications seems to indicate that checking all 4 DAT lines during voltage switch is optional i.e. only 1 of the lines must be checked. If that is true then we could change all the drivers over to check just DAT0, and expect that to work for both busy signalling and SD voltage switch checks. So it seems to me card_busy still needs to be sorted out first.
On Thu, 2016-05-12 at 13:29 +0300, Adrian Hunter wrote: > On 12/05/16 10:00, Chaotian Jing wrote: > > On Wed, 2016-05-11 at 10:50 +0300, Adrian Hunter wrote: > >> On 04/05/16 09:54, Chaotian Jing wrote: > >>> 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. > >>> > >>> this patch drops CMD13 when doing speed mode switch, if host do not > >>> support MMC_CAP_WAIT_WHILE_BUSY and there is no ops->card_busy(), > >>> then the only way is to wait a fixed timeout. > >> > >> This looks like it should be 3 patches: > >> 1. Change __mmc_switch > >> 2. Change HS200 and HS400 selection > >> 3. Change HS selection > >> > >> However there is another problem: card_busy is not the same as busy signal - > >> see below. So that needs to be sorted out first. > >> > > We should make that card_busy() is the same with busy signal asserted. > > as you know, if card was not in busy state, all data pins should be high > > level as it is pull-up by default. so that's no conflict to check card > > busy signal by DAT0 or DAT0 ~ DAT3. > > Potentially SDIO uses DAT1 for card interrupt, so that is a conflict right > there. > > Also SDHCI does it backwards (don't ask me why) and considers 0000 to be > busy, so there's another conflict. > > Some of the language in the SD and SDHCI specifications seems to indicate > that checking all 4 DAT lines during voltage switch is optional i.e. only 1 > of the lines must be checked. If that is true then we could change all the > drivers over to check just DAT0, and expect that to work for both busy > signalling and SD voltage switch checks. > > So it seems to me card_busy still needs to be sorted out first. One thing must point out is that the __mmc_switch() is only for MMC card. SD/SDIO will never use this interface. by the way, Per JEDEC SD3.0 spec, below is the quote from spec: "Completion of voltage switch sequence is checked by high level of DAT[3:0]. Any bit of DAT[3:0] can be checked depends on ability of the host." So that the implement of ops->card_busy() can be changed from check DAT[3:0] to only check DAT[0]. In fact, for SD/SDIO voltage switch, if switch success, all DAT pins are high level and if switch failed, all data pins are low level. >
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 4dbe3df..03ee7a4 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -962,7 +962,7 @@ static int mmc_select_hs(struct mmc_card *card) 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); + true, false, true); if (!err) mmc_set_timing(card->host, MMC_TIMING_MMC_HS); @@ -1056,7 +1056,6 @@ static int mmc_switch_status(struct mmc_card *card) 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; @@ -1068,9 +1067,6 @@ static int mmc_select_hs400(struct mmc_card *card) 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); @@ -1080,7 +1076,7 @@ static int mmc_select_hs400(struct mmc_card *card) 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); @@ -1090,11 +1086,9 @@ static int mmc_select_hs400(struct mmc_card *card) /* 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, @@ -1113,7 +1107,7 @@ static int mmc_select_hs400(struct mmc_card *card) 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); @@ -1124,11 +1118,9 @@ static int mmc_select_hs400(struct mmc_card *card) 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; @@ -1146,14 +1138,10 @@ int mmc_hs200_to_hs400(struct mmc_card *card) 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); @@ -1162,49 +1150,43 @@ int mmc_hs400_to_hs200(struct mmc_card *card) 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); + 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); @@ -1243,7 +1225,6 @@ static void mmc_select_driver_type(struct mmc_card *card) static int mmc_select_hs200(struct mmc_card *card) { struct mmc_host *host = card->host; - bool send_status = true; unsigned int old_timing; int err = -EINVAL; u8 val; @@ -1260,9 +1241,6 @@ static int mmc_select_hs200(struct mmc_card *card) 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. @@ -1274,20 +1252,18 @@ static int mmc_select_hs200(struct mmc_card *card) 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) diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c index 62355bd..32de144 100644 --- a/drivers/mmc/core/mmc_ops.c +++ b/drivers/mmc/core/mmc_ops.c @@ -480,6 +480,7 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, u32 status = 0; bool use_r1b_resp = use_busy_signal; bool expired = false; + bool busy = false; mmc_retune_hold(host); @@ -535,19 +536,24 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, /* Must check status to be sure of no errors. */ timeout = jiffies + msecs_to_jiffies(timeout_ms); do { + /* + * Due to the possibility of being preempted after + * sending the status command, check the expiration + * time first. + */ + expired = time_after(jiffies, timeout); if (send_status) { - /* - * Due to the possibility of being preempted after - * sending the status command, check the expiration - * time first. - */ - expired = time_after(jiffies, timeout); err = __mmc_send_status(card, &status, ignore_crc); if (err) goto out; } if ((host->caps & MMC_CAP_WAIT_WHILE_BUSY) && use_r1b_resp) break; + if (host->ops->card_busy) { + if (!host->ops->card_busy(host)) + break; + busy = true; + } if (mmc_host_is_spi(host)) break; @@ -556,19 +562,20 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, * does'nt support MMC_CAP_WAIT_WHILE_BUSY, then we can only * rely on waiting for the stated timeout to be sufficient. */ - if (!send_status) { + if (!send_status && !host->ops->card_busy) { mmc_delay(timeout_ms); goto out; } /* Timeout if the device never leaves the program state. */ - if (expired && R1_CURRENT_STATE(status) == R1_STATE_PRG) { + if (expired && + (R1_CURRENT_STATE(status) == R1_STATE_PRG || busy)) { pr_err("%s: Card stuck in programming state! %s\n", mmc_hostname(host), __func__); err = -ETIMEDOUT; goto out; } - } while (R1_CURRENT_STATE(status) == R1_STATE_PRG); + } while (R1_CURRENT_STATE(status) == R1_STATE_PRG || busy); err = mmc_switch_status_error(host, status); out:
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. this patch drops CMD13 when doing speed mode switch, if host do not support MMC_CAP_WAIT_WHILE_BUSY and there is no ops->card_busy(), then the only way is to wait a fixed timeout. Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com> --- drivers/mmc/core/mmc.c | 82 ++++++++++++++++---------------------------- drivers/mmc/core/mmc_ops.c | 25 +++++++++----- 2 files changed, 45 insertions(+), 62 deletions(-)