Merge patch series "Remove UFS_DEVICE_QUIRK_DELAY_AFTER_LPM quirk"

Bao D. Nguyen <[e-mail]> says:

Multiple ufs device manufacturers request support for the
UFS_DEVICE_QUIRK_DELAY_AFTER_LPM quirk in the Qualcomm's platform
driver. After checking further with the major UFS manufacturers
engineering teams such as Samsung, Kioxia, SK Hynix and Micron, all
the manufacturers require this quirk. Since the quirk is needed by all
the ufs device manufacturers, remove the quirk in the ufs core driver
and implement a universal delay for all the ufs devices.

In addition to verifying with the public device's datasheets, the ufs
device manufacturer's engineering teams confirmed the required vcc
power-off time for the devices is a minimum of 1ms before vcc can be
powered on again. The existing 5ms delay implemented in the ufs core
driver seems too conservative, so replace the hard coded 5ms delay
with a variable default to 2ms setting to improve the system resume
latency. The platform drivers can override this setting as needed.

Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Martin K. Petersen <[e-mail]>

drivers/ufs/core/ufshcd.c

···
 	}
 
 	/*
-	 * Some UFS devices require delay after VCC power rail is turned-off.
+	 * All UFS devices require delay after VCC power rail is turned-off.
 	 */
-	if (vcc_off && hba->vreg_info.vcc &&
-		hba->dev_quirks & UFS_DEVICE_QUIRK_DELAY_AFTER_LPM)
-		usleep_range(5000, 5100);
+	if (vcc_off && hba->vreg_info.vcc && !hba->vreg_info.vcc->always_on)
+		usleep_range(hba->vcc_off_delay_us,
+			     hba->vcc_off_delay_us + 100);
 }
 
 #ifdef CONFIG_PM
···
 	hba->spm_lvl = ufs_get_desired_pm_lvl_for_dev_link_state(
 						UFS_SLEEP_PWR_MODE,
 						UIC_LINK_HIBERN8_STATE);
+
+	/*
+	 * Most ufs devices require 1ms delay after vcc is powered off before
+	 * it can be powered on again. Set the default to 2ms. The platform
+	 * drivers can override this setting as needed.
+	 */
+	hba->vcc_off_delay_us = 2000;
 
 	init_completion(&hba->dev_cmd.complete);
 

drivers/ufs/host/ufs-mediatek.c

···
 static const struct ufs_dev_quirk ufs_mtk_dev_fixups[] = {
 	{ .wmanufacturerid = UFS_ANY_VENDOR,
 	  .model = UFS_ANY_MODEL,
-	  .quirk = UFS_DEVICE_QUIRK_DELAY_AFTER_LPM |
-		UFS_DEVICE_QUIRK_DELAY_BEFORE_LPM },
+	  .quirk = UFS_DEVICE_QUIRK_DELAY_BEFORE_LPM },
 	{ .wmanufacturerid = UFS_VENDOR_SKHYNIX,
 	  .model = "H9HQ21AFAMZDAR",
 	  .quirk = UFS_DEVICE_QUIRK_SUPPORT_EXTENDED_FEATURES },
···
 {
 	ufshcd_fixup_dev_quirks(hba, ufs_mtk_dev_fixups);
 
-	if (ufs_mtk_is_broken_vcc(hba) && hba->vreg_info.vcc &&
-	    (hba->dev_quirks & UFS_DEVICE_QUIRK_DELAY_AFTER_LPM)) {
+	if (ufs_mtk_is_broken_vcc(hba) && hba->vreg_info.vcc) {
 		hba->vreg_info.vcc->always_on = true;
 		/*
 		 * VCC will be kept always-on thus we don't
-		 * need any delay during regulator operations
+		 * need any delay before putting device's VCC in LPM mode.
 		 */
-		hba->dev_quirks &= ~(UFS_DEVICE_QUIRK_DELAY_BEFORE_LPM |
-			UFS_DEVICE_QUIRK_DELAY_AFTER_LPM);
+		hba->dev_quirks &= ~UFS_DEVICE_QUIRK_DELAY_BEFORE_LPM;
 	}
 
 	ufs_mtk_vreg_fix_vcc(hba);

drivers/ufs/host/ufs-qcom.c

···
 	{ .wmanufacturerid = UFS_VENDOR_SKHYNIX,
 	  .model = UFS_ANY_MODEL,
 	  .quirk = UFS_DEVICE_QUIRK_DELAY_BEFORE_LPM },
-	{ .wmanufacturerid = UFS_VENDOR_TOSHIBA,
-	  .model = UFS_ANY_MODEL,
-	  .quirk = UFS_DEVICE_QUIRK_DELAY_AFTER_LPM },
 	{ .wmanufacturerid = UFS_VENDOR_WDC,
 	  .model = UFS_ANY_MODEL,
 	  .quirk = UFS_DEVICE_QUIRK_HOST_PA_TACTIVATE },

include/ufs/ufs_quirks.h

···
 #define UFS_DEVICE_QUIRK_SUPPORT_EXTENDED_FEATURES (1 << 10)
 
 /*
- * Some UFS devices require delay after VCC power rail is turned-off.
- * Enable this quirk to introduce 5ms delays after VCC power-off during
- * suspend flow.
- */
-#define UFS_DEVICE_QUIRK_DELAY_AFTER_LPM        (1 << 11)
-
-/*
  * Some ufs devices may need more time to be in hibern8 before exiting.
  * Enable this quirk to give it an additional 100us.
  */

include/ufs/ufshcd.h

···
 	int critical_health_count;
 	atomic_t dev_lvl_exception_count;
 	u64 dev_lvl_exception_id;
+
+	u32 vcc_off_delay_us;
 };
 
 /**