Merge patch series "mei: connect to card in D3cold"

Alexander Usyskin <alexander.usyskin@intel.com> says:

When discrete graphic card enters D3cold th CSC engine is powered down.

On wakeup from the D3cold full HECI link reset is required.  The driver
should detect that firmware requests link reset and initiate the link
reset flow.

In the usual flow the connect IOCTL will trigger the wake from D3cold
and corresponding link reset.  The MEI driver invalidates all open
handles on link reset including the one that triggered the wake
rendering this connection unusable.  To break this loop make connect
detect that it is interrupted by link reset and retry connect attempt
after reset was completed.

Link: https://lore.kernel.org/r/20250918130435.3327400-1-alexander.usyskin@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 17 insertions, 42 deletions

diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 346633ebc6e6..d4612c659784 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -494,43 +494,6 @@ static int mei_me_hw_ready_wait(struct mei_device *dev)
 }
 
 /**
- * mei_me_check_fw_reset - check for the firmware reset error and exception conditions
- *
- * @dev: mei device
- */
-static void mei_me_check_fw_reset(struct mei_device *dev)
-{
-	struct mei_fw_status fw_status;
-	char fw_sts_str[MEI_FW_STATUS_STR_SZ] = {0};
-	int ret;
-	u32 fw_pm_event = 0;
-
-	if (!dev->saved_fw_status_flag)
-		goto end;
-
-	if (dev->gsc_reset_to_pxp == MEI_DEV_RESET_TO_PXP_PERFORMED) {
-		ret = mei_fw_status(dev, &fw_status);
-		if (!ret) {
-			fw_pm_event = fw_status.status[1] & PCI_CFG_HFS_2_PM_EVENT_MASK;
-			if (fw_pm_event != PCI_CFG_HFS_2_PM_CMOFF_TO_CMX_ERROR &&
-			    fw_pm_event != PCI_CFG_HFS_2_PM_CM_RESET_ERROR)
-				goto end;
-		} else {
-			dev_err(&dev->dev, "failed to read firmware status: %d\n", ret);
-		}
-	}
-
-	mei_fw_status2str(&dev->saved_fw_status, fw_sts_str, sizeof(fw_sts_str));
-	dev_warn(&dev->dev, "unexpected reset: fw_pm_event = 0x%x, dev_state = %u fw status = %s\n",
-		 fw_pm_event, dev->saved_dev_state, fw_sts_str);
-
-end:
-	if (dev->gsc_reset_to_pxp == MEI_DEV_RESET_TO_PXP_PERFORMED)
-		dev->gsc_reset_to_pxp = MEI_DEV_RESET_TO_PXP_DONE;
-	dev->saved_fw_status_flag = false;
-}
-
-/**
  * mei_me_hw_start - hw start routine
  *
  * @dev: mei device
@@ -540,8 +503,9 @@ static int mei_me_hw_start(struct mei_device *dev)
 {
 	int ret = mei_me_hw_ready_wait(dev);
 
-	if (kind_is_gsc(dev) || kind_is_gscfi(dev))
-		mei_me_check_fw_reset(dev);
+	if ((kind_is_gsc(dev) || kind_is_gscfi(dev)) &&
+	    dev->gsc_reset_to_pxp == MEI_DEV_RESET_TO_PXP_PERFORMED)
+		dev->gsc_reset_to_pxp = MEI_DEV_RESET_TO_PXP_DONE;
 	if (ret)
 		return ret;
 	dev_dbg(&dev->dev, "hw is ready\n");
@@ -1373,9 +1337,20 @@ irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id)
 	/*  check if we need to start the dev */
 	if (!mei_host_is_ready(dev)) {
 		if (mei_hw_is_ready(dev)) {
-			dev_dbg(&dev->dev, "we need to start the dev.\n");
-			dev->recvd_hw_ready = true;
-			wake_up(&dev->wait_hw_ready);
+			/* synchronized by dev mutex */
+			if (waitqueue_active(&dev->wait_hw_ready)) {
+				dev_dbg(&dev->dev, "we need to start the dev.\n");
+				dev->recvd_hw_ready = true;
+				wake_up(&dev->wait_hw_ready);
+			} else if (dev->dev_state != MEI_DEV_UNINITIALIZED &&
+				   dev->dev_state != MEI_DEV_POWERING_DOWN &&
+				   dev->dev_state != MEI_DEV_POWER_DOWN) {
+				dev_dbg(&dev->dev, "Force link reset.\n");
+				schedule_work(&dev->reset_work);
+			} else {
+				dev_dbg(&dev->dev, "Ignore this interrupt in state = %d\n",
+					dev->dev_state);
+			}
 		} else {
 			dev_dbg(&dev->dev, "Spurious Interrupt\n");
 		}