Commit c4217568797456bf2db2131a91c565596e88d588
Committed by
Haibo Chen
Haibo Chen
1 parent
4c95f33890
Exists in
smarc_8mm-imx_v2018.03_4.14.98_2.0.0_ga
and in
4 other branches
mmc: Do not poll using CMD13 when changing timing
When using CMD6 to switch eMMC card timing from HS200/HS400 to HS/legacy, do not poll for the completion status using CMD13, but rather wait 50mS. Once the card receives the CMD6 and starts executing it, the bus is in undefined state until both the card finishes executing the command and until the controller switches the bus to matching timing configuration. During this time, it is not possible to transport any commands or data across the bus, which includes the CMD13. Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com> Cc: Jaehoon Chung <jh80.chung@samsung.com> (cherry picked from commit 5dbade95cb7ebc1f3a309b00430ebf2b466d7aba) Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Showing 1 changed file with 20 additions and 8 deletions Side-by-side Diff
drivers/mmc/mmc.c
| ... | ... | @@ -748,7 +748,8 @@ |
| 748 | 748 | return err; |
| 749 | 749 | } |
| 750 | 750 | |
| 751 | -int mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value) | |
| 751 | +static int __mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value, | |
| 752 | + bool send_status) | |
| 752 | 753 | { |
| 753 | 754 | struct mmc_cmd cmd; |
| 754 | 755 | int timeout = 1000; |
| 755 | 756 | |
| 756 | 757 | |
| ... | ... | @@ -764,19 +765,29 @@ |
| 764 | 765 | while (retries > 0) { |
| 765 | 766 | ret = mmc_send_cmd(mmc, &cmd, NULL); |
| 766 | 767 | |
| 767 | - /* Waiting for the ready status */ | |
| 768 | - if (!ret) { | |
| 769 | - ret = mmc_send_status(mmc, timeout); | |
| 770 | - return ret; | |
| 768 | + if (ret) { | |
| 769 | + retries--; | |
| 770 | + continue; | |
| 771 | 771 | } |
| 772 | 772 | |
| 773 | - retries--; | |
| 773 | + if (!send_status) { | |
| 774 | + mdelay(50); | |
| 775 | + return 0; | |
| 776 | + } | |
| 777 | + | |
| 778 | + /* Waiting for the ready status */ | |
| 779 | + return mmc_send_status(mmc, timeout); | |
| 774 | 780 | } |
| 775 | 781 | |
| 776 | 782 | return ret; |
| 777 | 783 | |
| 778 | 784 | } |
| 779 | 785 | |
| 786 | +int mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value) | |
| 787 | +{ | |
| 788 | + return __mmc_switch(mmc, set, index, value, true); | |
| 789 | +} | |
| 790 | + | |
| 780 | 791 | static int mmc_set_card_speed(struct mmc *mmc, enum bus_mode mode, |
| 781 | 792 | bool hsdowngrade) |
| 782 | 793 | { |
| ... | ... | @@ -812,8 +823,9 @@ |
| 812 | 823 | default: |
| 813 | 824 | return -EINVAL; |
| 814 | 825 | } |
| 815 | - err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING, | |
| 816 | - speed_bits); | |
| 826 | + | |
| 827 | + err = __mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING, | |
| 828 | + speed_bits, !hsdowngrade); | |
| 817 | 829 | if (err) |
| 818 | 830 | return err; |
| 819 | 831 |