diff mbox series

[v4,02/10] mmc: mmci: Unwind big if() clause

Message ID 20230405-pl180-busydetect-fix-v4-2-df9c8c504353@linaro.org
State Superseded
Headers show
Series Fix busydetect on Ux500 PL180/MMCI | expand

Commit Message

Linus Walleij June 13, 2023, 8:34 p.m. UTC
This does two things: firsr replace the hard-to-read long
if-expression:

  if (!host->busy_status && !(status & err_msk) &&
      (readl(base + MMCISTATUS) & host->variant->busy_detect_flag)) {

With the more readable:

  if (!host->busy_status && !(status & err_msk)) {
     status = readl(base + MMCISTATUS);
     if (status & host->variant->busy_detect_flag) {

Second notice that the re-read MMCISTATUS register is now
stored into the status variable, using logic OR because what
if something else changed too?

While we are at it, explain what the function is doing.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v3->v4:
- No changes.
ChangeLog v2->v3:
- Rebased.
ChangeLog v1->v2:
- Only assign the cached status in host->busy_status if
  we have busy detect signalling going on.
---
 drivers/mmc/host/mmci.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 0a4b6b6e0f03..eee449f90915 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -654,6 +654,13 @@  static u32 ux500v2_get_dctrl_cfg(struct mmci_host *host)
 	return MCI_DPSM_ENABLE | (host->data->blksz << 16);
 }
 
+/*
+ * ux500_busy_complete() - this will wait until the busy status
+ * goes off, saving any status that occur in the meantime into
+ * host->busy_status until we know the card is not busy any more.
+ * The function returns true when the busy detection is ended
+ * and we should continue processing the command.
+ */
 static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)
 {
 	void __iomem *base = host->base;
@@ -671,14 +678,16 @@  static bool ux500_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)
 	 * while, to allow it to be set, but tests indicates that it
 	 * isn't needed.
 	 */
-	if (!host->busy_status && !(status & err_msk) &&
-	    (readl(base + MMCISTATUS) & host->variant->busy_detect_flag)) {
-		writel(readl(base + MMCIMASK0) |
-		       host->variant->busy_detect_mask,
-		       base + MMCIMASK0);
+	if (!host->busy_status && !(status & err_msk)) {
+		status = readl(base + MMCISTATUS);
+		if (status & host->variant->busy_detect_flag) {
+			writel(readl(base + MMCIMASK0) |
+			       host->variant->busy_detect_mask,
+			       base + MMCIMASK0);
 
-		host->busy_status = status & (MCI_CMDSENT | MCI_CMDRESPEND);
-		return false;
+			host->busy_status = status & (MCI_CMDSENT | MCI_CMDRESPEND);
+			return false;
+		}
 	}
 
 	/*