diff mbox series

[09/13] mmc: mmci: Use a switch statement machine

Message ID 20230405-pl180-busydetect-fix-v1-9-28ac19a74e5e@linaro.org (mailing list archive)
State New, archived
Headers show
Series Fix busydetect on Ux500 PL180/MMCI | expand

Commit Message

Linus Walleij April 5, 2023, 6:50 a.m. UTC
As is custom, use a big switch statement to transition
between the edges of the state machine inside
the ux500 ->busy_complete callback.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/mmc/host/mmci.c | 34 ++++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)
diff mbox series

Patch

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 734e8364b2f6..626467c212d6 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -676,6 +676,12 @@  static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)
 		goto out_ret_state;
 	}
 
+	/*
+	 * The state transitions are encoded in a state machine crossing
+	 * the edges in this switch statement.
+	 */
+	switch (host->busy_state) {
+
 	/*
 	 * Before unmasking for the busy end IRQ, confirm that the
 	 * command was sent successfully. To keep track of having a
@@ -686,7 +692,7 @@  static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)
 	 * it starts signaling busy on DAT0, hence re-read the
 	 * MMCISTATUS register here, to allow the busy bit to be set.
 	 */
-	if (host->busy_state == MMCI_BUSY_IDLE) {
+	case MMCI_BUSY_IDLE:
 		host->busy_status = status & (MCI_CMDSENT | MCI_CMDRESPEND);
 		while (retries) {
 			status = readl(base + MMCISTATUS);
@@ -706,8 +712,7 @@  static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)
 		writel(readl(base + MMCIMASK0) &
 		       ~host->variant->busy_detect_mask, base + MMCIMASK0);
 		host->busy_state = MMCI_BUSY_DONE;
-		goto out_ret_state;
-	}
+		break;
 
 	/*
 	 * If there is a command in-progress that has been successfully
@@ -720,12 +725,11 @@  static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)
 	 * both the start and the end interrupts needs to be cleared,
 	 * one after the other. So, clear the busy start IRQ here.
 	 */
-	if (host->busy_state == MMCI_BUSY_WAITING_FOR_IRQS) {
+	case MMCI_BUSY_WAITING_FOR_IRQS:
 		if (status & host->variant->busy_detect_flag) {
 			host->busy_status |= status & (MCI_CMDSENT | MCI_CMDRESPEND);
 			writel(host->variant->busy_detect_mask, base + MMCICLEAR);
 			host->busy_state = MMCI_BUSY_START_IRQ;
-			goto out_ret_state;
 		} else {
 			dev_dbg(mmc_dev(host->mmc),
 				"lost busy status when waiting for busy start IRQ\n");
@@ -734,16 +738,14 @@  static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)
 			       ~host->variant->busy_detect_mask, base + MMCIMASK0);
 			host->busy_state = MMCI_BUSY_DONE;
 			host->busy_status = 0;
-			goto out_ret_state;
 		}
-	}
+		break;
 
-	if (host->busy_state == MMCI_BUSY_START_IRQ) {
+	case MMCI_BUSY_START_IRQ:
 		if (status & host->variant->busy_detect_flag) {
 			host->busy_status |= status & (MCI_CMDSENT | MCI_CMDRESPEND);
 			writel(host->variant->busy_detect_mask, base + MMCICLEAR);
 			host->busy_state = MMCI_BUSY_END_IRQ;
-			goto out_ret_state;
 		} else {
 			dev_dbg(mmc_dev(host->mmc),
 				"lost busy status when waiting for busy end IRQ\n");
@@ -752,9 +754,8 @@  static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)
 			       ~host->variant->busy_detect_mask, base + MMCIMASK0);
 			host->busy_state = MMCI_BUSY_DONE;
 			host->busy_status = 0;
-			goto out_ret_state;
 		}
-	}
+		break;
 
 	/*
 	 * If there is a command in-progress that has been successfully
@@ -762,11 +763,10 @@  static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)
 	 * the busy end IRQ. Clear and mask the IRQ, then continue to
 	 * process the command.
 	 */
-	if (host->busy_state == MMCI_BUSY_END_IRQ) {
+	case MMCI_BUSY_END_IRQ:
 		if (status & host->variant->busy_detect_flag) {
 			/* We should just get two IRQs for busy detect */
 			dev_err(mmc_dev(host->mmc), "spurious busy detect IRQ\n");
-			goto out_ret_state;
 		}
 
 		writel(host->variant->busy_detect_mask, base + MMCICLEAR);
@@ -775,9 +775,15 @@  static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)
 
 		host->busy_state = MMCI_BUSY_DONE;
 		host->busy_status = 0;
-	} else {
+		break;
+
+	case MMCI_BUSY_DONE:
+		break;
+
+	default:
 		dev_dbg(mmc_dev(host->mmc), "fell through on state %d\n",
 			host->busy_state);
+		break;
 	}
 
 out_ret_state: