openwrt/target/linux/bcm27xx/patches-6.6/950-0993-drivers-mmc-cqhci-clear-CQHCI_CTL-if-halt-fails.patch

From fe98179e184bdb0ff7061d1a026f82b749854720 Mon Sep 17 00:00:00 2001
From: Jonathan Bell <jonathan@raspberrypi.com>
Date: Tue, 26 Mar 2024 13:17:10 +0000
Subject: [PATCH 0993/1085] drivers: mmc: cqhci: clear CQHCI_CTL if halt fails

The eMMC spec says that in certain circumstances the controller can't
respond to a halt request - in practice, this occurs if a CMD
timeout happens (card went away/crashed).

Clear the halt request by writing 0 to CQHCI_CTL. Also fix a logic error
testing for halt in cqhci_request.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
---
 drivers/mmc/host/cqhci-core.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

--- a/drivers/mmc/host/cqhci-core.c
+++ b/drivers/mmc/host/cqhci-core.c
@@ -383,9 +383,11 @@ static void cqhci_off(struct mmc_host *m
 
 	err = readx_poll_timeout(cqhci_read_ctl, cq_host, reg,
 				 reg & CQHCI_HALT, 0, CQHCI_OFF_TIMEOUT);
-	if (err < 0)
+	if (err < 0) {
 		pr_err("%s: cqhci: CQE stuck on\n", mmc_hostname(mmc));
-	else
+		/* eMMC v5.1 B.2.8 recommends writing 0 to CQHCI_CTL if stuck */
+		cqhci_writel(cq_host, 0, CQHCI_CTL);
+	} else
 		pr_debug("%s: cqhci: CQE off\n", mmc_hostname(mmc));
 
 	if (cq_host->ops->post_disable)
@@ -612,7 +614,7 @@ static int cqhci_request(struct mmc_host
 		cqhci_writel(cq_host, 0, CQHCI_CTL);
 		mmc->cqe_on = true;
 		pr_debug("%s: cqhci: CQE on\n", mmc_hostname(mmc));
-		if (cqhci_readl(cq_host, CQHCI_CTL) && CQHCI_HALT) {
+		if (cqhci_readl(cq_host, CQHCI_CTL) & CQHCI_HALT) {
 			pr_err("%s: cqhci: CQE failed to exit halt state\n",
 			       mmc_hostname(mmc));
 		}
@@ -975,8 +977,11 @@ static bool cqhci_halt(struct mmc_host *
 
 	ret = cqhci_halted(cq_host);
 
-	if (!ret)
+	if (!ret) {
 		pr_warn("%s: cqhci: Failed to halt\n", mmc_hostname(mmc));
+		/* eMMC v5.1 B.2.8 recommends writing 0 to CQHCI_CTL if stuck */
+		cqhci_writel(cq_host, 0, CQHCI_CTL);
+	}
 
 	return ret;
 }