[PATCH] mmc: core: extend timeout and set min time for op_cond

[Huijin Park <huijin.park@xxxxxxxxxxx>]

This patch extends timeout to 2s and sets minimal interval time for
checking op_cond stuck problem.

Signed-off-by: Huijin Park <huijin.park@xxxxxxxxxxx>

diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index d63d1c735335..ccad6379d183 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -21,6 +21,7 @@
 
 #define MMC_BKOPS_TIMEOUT_MS		(120 * 1000) /* 120s */
 #define MMC_SANITIZE_TIMEOUT_MS		(240 * 1000) /* 240s */
+#define MMC_OP_COND_TIMEOUT_MS		(  2 * 1000) /*   2s */
 
 static const u8 tuning_blk_pattern_4bit[] = {
 	0xff, 0x0f, 0xff, 0x00, 0xff, 0xcc, 0xc3, 0xcc,
@@ -179,6 +180,47 @@ int mmc_go_idle(struct mmc_host *host)
 	return err;
 }
 
+static int ____mmc_poll_for_busy(struct mmc_host *host, unsigned int udelay_min,
+				 unsigned int timeout_ms,
+				 int (*busy_cb)(void *cb_data, bool *busy),
+				 void *cb_data)
+{
+	int err;
+	unsigned long timeout;
+	unsigned int udelay = udelay_min, udelay_max = 32768;
+	bool expired = false;
+	bool busy = false;
+
+	timeout = jiffies + msecs_to_jiffies(timeout_ms) + 1;
+	do {
+		/*
+		 * Due to the possibility of being preempted while polling,
+		 * check the expiration time first.
+		 */
+		expired = time_after(jiffies, timeout);
+
+		err = (*busy_cb)(cb_data, &busy);
+		if (err)
+			return err;
+
+		/* Timeout if the device still remains busy. */
+		if (expired && busy) {
+			pr_err("%s: Card stuck being busy! %s\n",
+				mmc_hostname(host), __func__);
+			return -ETIMEDOUT;
+		}
+
+		/* Throttle the polling rate to avoid hogging the CPU. */
+		if (busy) {
+			usleep_range(udelay, udelay * 2);
+			if (udelay < udelay_max)
+				udelay *= 2;
+		}
+	} while (busy);
+
+	return 0;
+}
+
 static int __mmc_send_op_cond_cb(void *cb_data, bool *busy)
 {
 	struct mmc_op_cond_busy_data *data = cb_data;
@@ -232,7 +274,8 @@ int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
 	cmd.arg = mmc_host_is_spi(host) ? 0 : ocr;
 	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R3 | MMC_CMD_BCR;
 
-	err = __mmc_poll_for_busy(host, 1000, &__mmc_send_op_cond_cb, &cb_data);
+	err = ____mmc_poll_for_busy(host, 1000, MMC_OP_COND_TIMEOUT_MS,
+				    &__mmc_send_op_cond_cb, &cb_data);
 	if (err)
 		return err;
 
-- 
2.17.1