[PATCH 3/6] HID: intel-ish-ipc: Reset clients state on resume from D3

[Zhang Lixu <lixu.zhang@intel.com>]

When ISH resumes from D3, the connection between ishtp clients and firmware
is lost. The ish_resume() function schedules resume_work asynchronously to
re-initiate the connection and then returns immediately. This can cause a
race where the upper-layer ishtp client driver's .resume() may execute
before the connection is fully restored, leaving the client in a stale
connected state. If the client sends messages during this window, the
firmware cannot respond.

To avoid this, reset the ishtp clients' state before returning from
ish_resume() if ISH is resuming from D3.

Signed-off-by: Zhang Lixu <lixu.zhang@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 drivers/hid/intel-ish-hid/ipc/pci-ish.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/intel-ish-hid/ipc/pci-ish.c b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
index 9d150ce234f2..ccd195adbbd6 100644
--- a/drivers/hid/intel-ish-hid/ipc/pci-ish.c
+++ b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
@@ -147,6 +147,12 @@ static inline bool ish_should_enter_d0i3(struct pci_dev *pdev)
 
 static inline bool ish_should_leave_d0i3(struct pci_dev *pdev)
 {
+	struct ishtp_device *dev = pci_get_drvdata(pdev);
+	u32 fwsts = dev->ops->get_fw_status(dev);
+
+	if (dev->suspend_flag || !IPC_IS_ISH_ILUP(fwsts))
+		return false;
+
 	return !pm_resume_via_firmware() || pdev->device == PCI_DEVICE_ID_INTEL_ISH_CHV;
 }
 
@@ -277,10 +283,8 @@ static void __maybe_unused ish_resume_handler(struct work_struct *work)
 {
 	struct pci_dev *pdev = to_pci_dev(ish_resume_device);
 	struct ishtp_device *dev = pci_get_drvdata(pdev);
-	uint32_t fwsts = dev->ops->get_fw_status(dev);
 
-	if (ish_should_leave_d0i3(pdev) && !dev->suspend_flag
-			&& IPC_IS_ISH_ILUP(fwsts)) {
+	if (ish_should_leave_d0i3(pdev)) {
 		if (device_may_wakeup(&pdev->dev))
 			disable_irq_wake(pdev->irq);
 
@@ -384,6 +388,10 @@ static int __maybe_unused ish_resume(struct device *device)
 	ish_resume_device = device;
 	dev->resume_flag = 1;
 
+	/* If ISH resume from D3, reset ishtp clients before return */
+	if (!ish_should_leave_d0i3(pdev))
+		ishtp_reset_handler(dev);
+
 	schedule_work(&resume_work);
 
 	return 0;
-- 
2.43.0