openwrt/target/linux/bcm27xx/patches-6.6/950-0988-drivers-sdhci-brcmstb-work-around-mystery-CQE-CMD_ID.patch

From fc20eb4e650bf793bd6b3d804a63b67085c55f08 Mon Sep 17 00:00:00 2001
From: Jonathan Bell <jonathan@raspberrypi.com>
Date: Fri, 22 Mar 2024 14:22:55 +0000
Subject: [PATCH 0988/1085] drivers: sdhci-brcmstb: work around mystery CQE
 CMD_IDLE_TIMER trampling

For unknown reasons the controller seems to reset the idle polling timer
interval on CQE enable/disable to 8 clocks which is extremely short.

Just use the reset value in the eMMC spec (4096 clock periods which at
200MHz is ~20uS).

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

--- a/drivers/mmc/host/sdhci-brcmstb.c
+++ b/drivers/mmc/host/sdhci-brcmstb.c
@@ -339,6 +339,7 @@ static void sdhci_brcmstb_dumpregs(struc
 static void sdhci_brcmstb_cqe_enable(struct mmc_host *mmc)
 {
 	struct sdhci_host *host = mmc_priv(mmc);
+	struct cqhci_host *cq_host = mmc->cqe_private;
 	u32 reg;
 
 	reg = sdhci_readl(host, SDHCI_PRESENT_STATE);
@@ -348,6 +349,9 @@ static void sdhci_brcmstb_cqe_enable(str
 	}
 
 	sdhci_cqe_enable(mmc);
+
+	/* Reset CMD13 polling timer back to eMMC specification default */
+	cqhci_writel(cq_host, 0x00011000, CQHCI_SSC1);
 }
 
 static const struct cqhci_host_ops sdhci_brcmstb_cqhci_ops = {