[PATCH 5.15.y 1/2] scsi: ufs: ufs-pci: Fix hibernate state transition for Intel MTL-like host controllers

[PATCH 5.15.y 1/2] scsi: ufs: ufs-pci: Fix hibernate state transition for Intel MTL-like host controllers

[Adrian Hunter]

From: Archana Patni <archana.patni@intel.com>

commit 4428ddea832cfdb63e476eb2e5c8feb5d36057fe upstream.

UFSHCD core disables the UIC completion interrupt when issuing UIC
hibernation commands, and re-enables it afterwards if it was enabled to
start with, refer ufshcd_uic_pwr_ctrl(). For Intel MTL-like host
controllers, accessing the register to re-enable the interrupt disrupts
the state transition.

Use hibern8_notify variant operation to disable the interrupt during the
entire hibernation, thereby preventing the disruption.

Fixes: 4049f7acef3e ("scsi: ufs: ufs-pci: Add support for Intel MTL")
Cc: stable@vger.kernel.org
Signed-off-by: Archana Patni <archana.patni@intel.com>
Link: https://lore.kernel.org/r/20250723165856.145750-2-adrian.hunter@intel.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/scsi/ufs/ufshcd-pci.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd-pci.c b/drivers/scsi/ufs/ufshcd-pci.c
index 0920530a72d2..11071c132c1d 100644
--- a/drivers/scsi/ufs/ufshcd-pci.c
+++ b/drivers/scsi/ufs/ufshcd-pci.c
@@ -203,6 +203,32 @@ static int ufs_intel_lkf_apply_dev_quirks(struct ufs_hba *hba)
 	return ret;
 }
 
+static void ufs_intel_ctrl_uic_compl(struct ufs_hba *hba, bool enable)
+{
+	u32 set = ufshcd_readl(hba, REG_INTERRUPT_ENABLE);
+
+	if (enable)
+		set |= UIC_COMMAND_COMPL;
+	else
+		set &= ~UIC_COMMAND_COMPL;
+	ufshcd_writel(hba, set, REG_INTERRUPT_ENABLE);
+}
+
+static void ufs_intel_mtl_h8_notify(struct ufs_hba *hba,
+				    enum uic_cmd_dme cmd,
+				    enum ufs_notify_change_status status)
+{
+	/*
+	 * Disable UIC COMPL INTR to prevent access to UFSHCI after
+	 * checking HCS.UPMCRS
+	 */
+	if (status == PRE_CHANGE && cmd == UIC_CMD_DME_HIBER_ENTER)
+		ufs_intel_ctrl_uic_compl(hba, false);
+
+	if (status == POST_CHANGE && cmd == UIC_CMD_DME_HIBER_EXIT)
+		ufs_intel_ctrl_uic_compl(hba, true);
+}
+
 #define INTEL_ACTIVELTR		0x804
 #define INTEL_IDLELTR		0x808
 
@@ -476,6 +502,7 @@ static struct ufs_hba_variant_ops ufs_intel_mtl_hba_vops = {
 	.init			= ufs_intel_mtl_init,
 	.exit			= ufs_intel_common_exit,
 	.hce_enable_notify	= ufs_intel_hce_enable_notify,
+	.hibern8_notify		= ufs_intel_mtl_h8_notify,
 	.link_startup_notify	= ufs_intel_link_startup_notify,
 	.resume			= ufs_intel_resume,
 	.device_reset		= ufs_intel_device_reset,
-- 
2.48.1

[PATCH 5.15.y 2/2] scsi: ufs: ufs-pci: Fix default runtime and system PM levels

[Adrian Hunter]

commit 6de7435e6b81fe52c0ab4c7e181f6b5decd18eb1 upstream.

Intel MTL-like host controllers support auto-hibernate.  Using
auto-hibernate with manual (driver initiated) hibernate produces more
complex operation.  For example, the host controller will have to exit
auto-hibernate simply to allow the driver to enter hibernate state
manually.  That is not recommended.

The default rpm_lvl and spm_lvl is 3, which includes manual hibernate.

Change the default values to 2, which does not.

Note, to be simpler to backport to stable kernels, utilize the UFS PCI
driver's ->late_init() call back.  Recent commits have made it possible
to set up a controller-specific default in the regular ->init() call
back, but not all stable kernels have those changes.

Fixes: 4049f7acef3e ("scsi: ufs: ufs-pci: Add support for Intel MTL")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250723165856.145750-3-adrian.hunter@intel.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/scsi/ufs/ufshcd-pci.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufshcd-pci.c b/drivers/scsi/ufs/ufshcd-pci.c
index 11071c132c1d..ec483ece09b6 100644
--- a/drivers/scsi/ufs/ufshcd-pci.c
+++ b/drivers/scsi/ufs/ufshcd-pci.c
@@ -454,10 +454,23 @@ static int ufs_intel_adl_init(struct ufs_hba *hba)
 	return ufs_intel_common_init(hba);
 }
 
+static void ufs_intel_mtl_late_init(struct ufs_hba *hba)
+{
+	hba->rpm_lvl = UFS_PM_LVL_2;
+	hba->spm_lvl = UFS_PM_LVL_2;
+}
+
 static int ufs_intel_mtl_init(struct ufs_hba *hba)
 {
+	struct ufs_host *ufs_host;
+	int err;
+
 	hba->caps |= UFSHCD_CAP_CRYPTO | UFSHCD_CAP_WB_EN;
-	return ufs_intel_common_init(hba);
+	err = ufs_intel_common_init(hba);
+	/* Get variant after it is set in ufs_intel_common_init() */
+	ufs_host = ufshcd_get_variant(hba);
+	ufs_host->late_init = ufs_intel_mtl_late_init;
+	return err;
 }
 
 static struct ufs_hba_variant_ops ufs_intel_cnl_hba_vops = {
-- 
2.48.1