[PATCH] mmc: Some Micron eMMC devices cause reboot to hang

[Al Cooper <alcooperx@gmail.com>]

When using eMMC as the boot device, some Micron eMMC devices will
cause reboot to hang. This is a result of the eMMC device not going
into boot mode after the hardware sends CMD0 to reset the eMMC
device. This only happens if the kernel driver sends CMD5 (SLEEP_WAKE),
to put the device into sleep state, before restarting the system.
The fix is to add a quirk that avoids sending the SLEEP command
and to use MMC_FIXUP to set the quirk for these Micron devices.

Signed-off-by: Al Cooper <alcooperx@gmail.com>
---
 drivers/mmc/core/mmc.c    | 3 ++-
 drivers/mmc/core/quirks.h | 8 ++++++++
 include/linux/mmc/card.h  | 1 +
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 4203303f946a..4d69e8f8fe59 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1895,7 +1895,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 
 static int mmc_can_sleep(struct mmc_card *card)
 {
-	return (card && card->ext_csd.rev >= 3);
+	return card && card->ext_csd.rev >= 3 &&
+		((card->quirks & MMC_QUIRK_BROKEN_SLEEP) == 0);
 }
 
 static int mmc_sleep(struct mmc_host *host)
diff --git a/drivers/mmc/core/quirks.h b/drivers/mmc/core/quirks.h
index 472fa2fdcf13..7263187b6323 100644
--- a/drivers/mmc/core/quirks.h
+++ b/drivers/mmc/core/quirks.h
@@ -99,6 +99,14 @@ static const struct mmc_fixup mmc_blk_fixups[] = {
 	MMC_FIXUP("V10016", CID_MANFID_KINGSTON, CID_OEMID_ANY, add_quirk_mmc,
 		  MMC_QUIRK_TRIM_BROKEN),
 
+	/*
+	 * Some Micron eMMC devices will not go into boot mode on
+	 * CMD0 arg: 0XF0F0F0F0 after going into SLEEP state.
+	 * This will hang a reboot.
+	 */
+	MMC_FIXUP(CID_NAME_ANY, CID_MANFID_NUMONYX, 0x014e, add_quirk_mmc,
+		  MMC_QUIRK_BROKEN_SLEEP),
+
 	END_FIXUP
 };
 
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 7d46411ffaa2..0cdddcb5e17d 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -270,6 +270,7 @@ struct mmc_card {
 #define MMC_QUIRK_BROKEN_IRQ_POLLING	(1<<11)	/* Polling SDIO_CCCR_INTx could create a fake interrupt */
 #define MMC_QUIRK_TRIM_BROKEN	(1<<12)		/* Skip trim */
 #define MMC_QUIRK_BROKEN_HPI	(1<<13)		/* Disable broken HPI support */
+#define MMC_QUIRK_BROKEN_SLEEP	(1<<14)		/* Broken sleep mode */
 
 	bool			reenable_cmdq;	/* Re-enable Command Queue */
 
-- 
2.17.1