mmc: sdhci-tegra: Issue CMD and DAT resets together

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2144641

commit acc1395
Author: Prathamesh Shete <pshete@nvidia.com>
Date: Tue, 6 Dec 2022 17:59:45 +0100

    In case of error condition to avoid system crash Tegra SDMMC controller
    requires CMD and DAT resets issued together. SDHCI controller FSM goes
    into bad state due to rapid SD card hot-plug event. Issuing reset on the
    CMD FSM before DATA FSM results in kernel panic, hence add support to
    issue CMD and DAT resets together.

    This is applicable to Tegra186 and later chips.

    Signed-off-by: Aniruddha TVS Rao <anrao@nvidia.com>
    Signed-off-by: Prathamesh Shete <pshete@nvidia.com>
    Acked-by: Adrian Hunter <adrian.hunter@intel.com>
    Acked-by: Thierry Reding <treding@nvidia.com>
    Signed-off-by: Thierry Reding <treding@nvidia.com>
    Link: https://lore.kernel.org/r/20221206165945.3551774-7-thierry.reding@gmail.com
    Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Signed-off-by: Mark Salter <msalter@redhat.com>

Author: mosalter

drivers/mmc/host/sdhci-tegra.c

@@ -1532,7 +1532,8 @@ static const struct sdhci_pltfm_data sdhci_tegra186_pdata = {
 		  SDHCI_QUIRK_NO_HISPD_BIT |
 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
-	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
+	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
+		   SDHCI_QUIRK2_ISSUE_CMD_DAT_RESET_TOGETHER,
 	.ops  = &tegra186_sdhci_ops,
 };
 

drivers/mmc/host/sdhci.c

@@ -269,6 +269,11 @@ enum sdhci_reset_reason {
 
 static void sdhci_reset_for_reason(struct sdhci_host *host, enum sdhci_reset_reason reason)
 {
+	if (host->quirks2 & SDHCI_QUIRK2_ISSUE_CMD_DAT_RESET_TOGETHER) {
+		sdhci_do_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
+		return;
+	}
+
 	switch (reason) {
 	case SDHCI_RESET_FOR_INIT:
 		sdhci_do_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);

drivers/mmc/host/sdhci.h

@@ -475,6 +475,8 @@ struct sdhci_host {
  * block count.
  */
 #define SDHCI_QUIRK2_USE_32BIT_BLK_CNT			(1<<18)
+/* Issue CMD and DATA reset together */
+#define SDHCI_QUIRK2_ISSUE_CMD_DAT_RESET_TOGETHER	(1<<19)
 
 	int irq;		/* Device IRQ */
 	void __iomem *ioaddr;	/* Mapped address */