MLK-12462-1 mmc: core: add MMC_PM_IGNORE_PM_NOTIFY feature

With igore pm notify feature, MMC core will not re-detect card after system suspend/resume. This is needed for some special cards like Broadcom WiFi which can't work propertly on card re-detect after system resume. Signed-off-by: Dong Aisheng <[email protected]> (cherry picked from commit 3a4a074)
voipac · Mar 1, 2016 · e42f70d · e42f70d
1 parent cc78790
commit e42f70d
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Showing 3 changed files with 9 additions and 3 deletions.
diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt
@@ -70,7 +70,8 @@ polarity is in effect.
 Optional SDIO properties:
 - keep-power-in-suspend: Preserves card power during a suspend/resume cycle
 - enable-sdio-wakeup: Enables wake up of host system on SDIO IRQ assertion
-
+- pm-ignore-notify: Ignore mmc PM notify. This will prevent MMC core automatically
+		    to re-detect cards after sysem resume back.
 
 MMC power sequences:
 --------------------

diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
@@ -517,6 +517,8 @@ int mmc_of_parse(struct mmc_host *host)
 		host->pm_caps |= MMC_PM_KEEP_POWER;
 	if (of_property_read_bool(np, "enable-sdio-wakeup"))
 		host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
+	if (of_get_property(np, "pm-ignore-notify", NULL))
+		host->pm_caps |= MMC_PM_IGNORE_PM_NOTIFY;
 	if (of_property_read_bool(np, "mmc-ddr-1_8v"))
 		host->caps |= MMC_CAP_1_8V_DDR;
 	if (of_property_read_bool(np, "mmc-ddr-1_2v"))
@@ -651,7 +653,8 @@ int mmc_add_host(struct mmc_host *host)
 	mmc_host_clk_sysfs_init(host);
 
 	mmc_start_host(host);
-	register_pm_notifier(&host->pm_notify);
+	if (!(host->pm_caps& MMC_PM_IGNORE_PM_NOTIFY))
+		register_pm_notifier(&host->pm_notify);
 
 	return 0;
 }
@@ -668,7 +671,8 @@ EXPORT_SYMBOL(mmc_add_host);
  */
 void mmc_remove_host(struct mmc_host *host)
 {
-	unregister_pm_notifier(&host->pm_notify);
+	if (!(host->pm_caps& MMC_PM_IGNORE_PM_NOTIFY))
+		unregister_pm_notifier(&host->pm_notify);
 	mmc_stop_host(host);
 
 #ifdef CONFIG_DEBUG_FS

diff --git a/include/linux/mmc/pm.h b/include/linux/mmc/pm.h
@@ -26,5 +26,6 @@ typedef unsigned int mmc_pm_flag_t;
 
 #define MMC_PM_KEEP_POWER	(1 << 0)	/* preserve card power during suspend */
 #define MMC_PM_WAKE_SDIO_IRQ	(1 << 1)	/* wake up host system on SDIO IRQ assertion */
+#define MMC_PM_IGNORE_PM_NOTIFY	(1 << 2)	/* ignore mmc pm notify */
 
 #endif /* LINUX_MMC_PM_H */