From 76bfc7ccc2fa9d382576f6013b57a0ef93d5a722 Mon Sep 17 00:00:00 2001 From: Huijin Park Date: Thu, 4 Nov 2021 15:32:31 +0900 Subject: [PATCH] mmc: core: adjust polling interval for CMD1 In mmc_send_op_cond(), loops are continuously performed at the same interval of 10 ms. However the behaviour is not good for some eMMC which can be out from a busy state earlier than 10 ms if normal. Rather than fixing about the interval time in mmc_send_op_cond(), let's instead convert into using the common __mmc_poll_for_busy(). The reason for adjusting the interval time is that it is important to reduce the eMMC initialization time, especially in devices that use eMMC as rootfs. Test log(eMMC:KLM8G1GETF-B041): before: 12 ms (0.311016 - 0.298729) [ 0.295823] mmc0: starting CMD0 arg 00000000 flags 000000c0 [ 0.298729] mmc0: starting CMD1 arg 40000080 flags 000000e1<-start [ 0.311016] mmc0: starting CMD1 arg 40000080 flags 000000e1<-finish [ 0.311336] mmc0: starting CMD2 arg 00000000 flags 00000007 after: 2 ms (0.301270 - 0.298762) [ 0.295862] mmc0: starting CMD0 arg 00000000 flags 000000c0 [ 0.298762] mmc0: starting CMD1 arg 40000080 flags 000000e1<-start [ 0.299067] mmc0: starting CMD1 arg 40000080 flags 000000e1 [ 0.299441] mmc0: starting CMD1 arg 40000080 flags 000000e1 [ 0.299879] mmc0: starting CMD1 arg 40000080 flags 000000e1 [ 0.300446] mmc0: starting CMD1 arg 40000080 flags 000000e1 [ 0.301270] mmc0: starting CMD1 arg 40000080 flags 000000e1<-finish [ 0.301572] mmc0: starting CMD2 arg 00000000 flags 00000007 Signed-off-by: Huijin Park Link: https://lore.kernel.org/r/20211104063231.2115-3-huijin.park@samsung.com Signed-off-by: Ulf Hansson --- drivers/mmc/core/mmc_ops.c | 83 +++++++++++++++++++++++++------------- 1 file changed, 54 insertions(+), 29 deletions(-) diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c index 9946733a34c6..d63d1c735335 100644 --- a/drivers/mmc/core/mmc_ops.c +++ b/drivers/mmc/core/mmc_ops.c @@ -58,6 +58,12 @@ struct mmc_busy_data { enum mmc_busy_cmd busy_cmd; }; +struct mmc_op_cond_busy_data { + struct mmc_host *host; + u32 ocr; + struct mmc_command *cmd; +}; + int __mmc_send_status(struct mmc_card *card, u32 *status, unsigned int retries) { int err; @@ -173,43 +179,62 @@ int mmc_go_idle(struct mmc_host *host) return err; } +static int __mmc_send_op_cond_cb(void *cb_data, bool *busy) +{ + struct mmc_op_cond_busy_data *data = cb_data; + struct mmc_host *host = data->host; + struct mmc_command *cmd = data->cmd; + u32 ocr = data->ocr; + int err = 0; + + err = mmc_wait_for_cmd(host, cmd, 0); + if (err) + return err; + + if (mmc_host_is_spi(host)) { + if (!(cmd->resp[0] & R1_SPI_IDLE)) { + *busy = false; + return 0; + } + } else { + if (cmd->resp[0] & MMC_CARD_BUSY) { + *busy = false; + return 0; + } + } + + *busy = true; + + /* + * According to eMMC specification v5.1 section 6.4.3, we + * should issue CMD1 repeatedly in the idle state until + * the eMMC is ready. Otherwise some eMMC devices seem to enter + * the inactive mode after mmc_init_card() issued CMD0 when + * the eMMC device is busy. + */ + if (!ocr && !mmc_host_is_spi(host)) + cmd->arg = cmd->resp[0] | BIT(30); + + return 0; +} + int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr) { struct mmc_command cmd = {}; - int i, err = 0; + int err = 0; + struct mmc_op_cond_busy_data cb_data = { + .host = host, + .ocr = ocr, + .cmd = &cmd + }; cmd.opcode = MMC_SEND_OP_COND; cmd.arg = mmc_host_is_spi(host) ? 0 : ocr; cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R3 | MMC_CMD_BCR; - for (i = 100; i; i--) { - err = mmc_wait_for_cmd(host, &cmd, 0); - if (err) - break; - - /* wait until reset completes */ - if (mmc_host_is_spi(host)) { - if (!(cmd.resp[0] & R1_SPI_IDLE)) - break; - } else { - if (cmd.resp[0] & MMC_CARD_BUSY) - break; - } - - err = -ETIMEDOUT; - - mmc_delay(10); - - /* - * According to eMMC specification v5.1 section 6.4.3, we - * should issue CMD1 repeatedly in the idle state until - * the eMMC is ready. Otherwise some eMMC devices seem to enter - * the inactive mode after mmc_init_card() issued CMD0 when - * the eMMC device is busy. - */ - if (!ocr && !mmc_host_is_spi(host)) - cmd.arg = cmd.resp[0] | BIT(30); - } + err = __mmc_poll_for_busy(host, 1000, &__mmc_send_op_cond_cb, &cb_data); + if (err) + return err; if (rocr && !mmc_host_is_spi(host)) *rocr = cmd.resp[0];