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mmc: core: Allow host controllers to require R1B for CMD6

It has turned out that some host controllers can't use R1B for CMD6 and other commands that have R1B associated with them. Therefore invent a new host cap, MMC_CAP_NEED_RSP_BUSY to let them specify this. In __mmc_switch(), let's check the flag and use it to prevent R1B responses from being converted into R1. Note that, this also means that the host are on its own, when it comes to manage the busy timeout.

Ulf Hansson committed 6 years ago

Commit 1292e3e1 parent 31e43f32 files · +5 −2Browse files

Unified · Split

2 files
  1. drivers/mmc/core/mmc_ops.c +4 −2
  2. include/linux/mmc/host.h +1 −0
drivers/mmc/core/mmc_ops.c+4−2
@@ -542,9 +542,11 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, · 541 unmodified lines
542 * If the max_busy_timeout of the host is specified, make sure it's542 * If the max_busy_timeout of the host is specified, make sure it's
543 * enough to fit the used timeout_ms. In case it's not, let's instruct543 * enough to fit the used timeout_ms. In case it's not, let's instruct
544 * the host to avoid HW busy detection, by converting to a R1 response544 * the host to avoid HW busy detection, by converting to a R1 response
545 * instead of a R1B.545 * instead of a R1B. Note, some hosts requires R1B, which also means
546 * they are on their own when it comes to deal with the busy timeout.
546 */547 */
547 if (host->max_busy_timeout && (timeout_ms > host->max_busy_timeout))548 if (!(host->caps & MMC_CAP_NEED_RSP_BUSY) && host->max_busy_timeout &&
549 (timeout_ms > host->max_busy_timeout))
548 use_r1b_resp = false;550 use_r1b_resp = false;
549 551
550 cmd.opcode = MMC_SWITCH;552 cmd.opcode = MMC_SWITCH;
include/linux/mmc/host.h+1−0
@@ -333,6 +333,7 @@ struct mmc_host { · 332 unmodified lines
333 MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | \333 MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | \
334 MMC_CAP_UHS_DDR50)334 MMC_CAP_UHS_DDR50)
335#define MMC_CAP_SYNC_RUNTIME_PM (1 << 21) /* Synced runtime PM suspends. */335#define MMC_CAP_SYNC_RUNTIME_PM (1 << 21) /* Synced runtime PM suspends. */
336#define MMC_CAP_NEED_RSP_BUSY (1 << 22) /* Commands with R1B can't use R1. */
336#define MMC_CAP_DRIVER_TYPE_A (1 << 23) /* Host supports Driver Type A */337#define MMC_CAP_DRIVER_TYPE_A (1 << 23) /* Host supports Driver Type A */
337#define MMC_CAP_DRIVER_TYPE_C (1 << 24) /* Host supports Driver Type C */338#define MMC_CAP_DRIVER_TYPE_C (1 << 24) /* Host supports Driver Type C */
338#define MMC_CAP_DRIVER_TYPE_D (1 << 25) /* Host supports Driver Type D */339#define MMC_CAP_DRIVER_TYPE_D (1 << 25) /* Host supports Driver Type D */