[PATCH V2 1/8] scsi: ufs: ufs-pci: Fix hibernate state transition for Intel MTL-like host controllers

Adrian Hunter
2025-07-23T16:59:12Z

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

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: 4049f7acef3eb ("scsi: ufs: ufs-pci: Add support for Intel MTL")
Cc: stable@vger.kernel.org
Signed-off-by: Archana Patni <archana.patni@intel.com>
---
drivers/ufs/host/ufshcd-pci.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/drivers/ufs/host/ufshcd-pci.c b/drivers/ufs/host/ufshcd-pci.c
index 996387906aa1..af1c272eef1c 100644
--- a/drivers/ufs/host/ufshcd-pci.c
+++ b/drivers/ufs/host/ufshcd-pci.c
@@ -216,6 +216,32 @@ 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

@@ -533,6 +559,7 @@ 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