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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ulf Hansson <[email protected]>

diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 9946733a34c6d1b0222b2184ac0880ef97bacb3c..d63d1c735335c21b8ca7261066b7330c0b2b2710 100644 (file)
--- 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];