mmc: core: Further prevent card detect during shutdown

Disabling card detect from the host's ->shutdown_pre() callback turned out
to not be the complete solution. More precisely, beyond the point when the
mmc_bus->shutdown() has been called, to gracefully power off the card, we
need to prevent card detect. Otherwise the mmc_rescan work may poll for the
card with a CMD13, to see if it's still alive, which then will fail and
hang as the card has already been powered off.

To fix this problem, let's disable mmc_rescan prior to power off the card
during shutdown.

Reported-by: Anthony Pighin <anthony.pighin@nokia.com>
Fixes: 66c915d ("mmc: core: Disable card detect during shutdown")
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Closes: https://lore.kernel.org/all/BN0PR08MB695133000AF116F04C3A9FFE83212@BN0PR08MB6951.namprd08.prod.outlook.com/
Tested-by: Anthony Pighin <anthony.pighin@nokia.com>
Message-ID: <20241125122446.18684-1-ulf.hansson@linaro.org>

Author: storulf

drivers/mmc/core/bus.c

@@ -149,6 +149,8 @@ static void mmc_bus_shutdown(struct device *dev)
 	if (dev->driver && drv->shutdown)
 		drv->shutdown(card);
 
+	__mmc_stop_host(host);
+
 	if (host->bus_ops->shutdown) {
 		ret = host->bus_ops->shutdown(host);
 		if (ret)

drivers/mmc/core/core.c

@@ -2335,6 +2335,9 @@ void mmc_start_host(struct mmc_host *host)
 
 void __mmc_stop_host(struct mmc_host *host)
 {
+	if (host->rescan_disable)
+		return;
+
 	if (host->slot.cd_irq >= 0) {
 		mmc_gpio_set_cd_wake(host, false);
 		disable_irq(host->slot.cd_irq);