ath11k: mhi: add error handling for suspend and resume

While reviewing the mhi.c I noticed we were just ignoring the errors coming
from MHI subsystem during suspend and resume. Add proper checks and warning
messages. Also pass the error value to callers.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03003-QCAHSPSWPL_V1_V2_SILICONZ_LITE-2
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220401173042.17467-3-kvalo@kernel.org

drivers/net/wireless/ath/ath11k/mhi.c

@@ -489,16 +489,34 @@ void ath11k_mhi_stop(struct ath11k_pci *ab_pci)
 	mhi_unprepare_after_power_down(ab_pci->mhi_ctrl);
 }
 
-void ath11k_mhi_suspend(struct ath11k_pci *ab_pci)
+int ath11k_mhi_suspend(struct ath11k_pci *ab_pci)
 {
-	mhi_pm_suspend(ab_pci->mhi_ctrl);
+	struct ath11k_base *ab = ab_pci->ab;
+	int ret;
+
+	ret = mhi_pm_suspend(ab_pci->mhi_ctrl);
+	if (ret) {
+		ath11k_warn(ab, "failed to suspend mhi: %d", ret);
+		return ret;
+	}
+
+	return 0;
 }
 
-void ath11k_mhi_resume(struct ath11k_pci *ab_pci)
+int ath11k_mhi_resume(struct ath11k_pci *ab_pci)
 {
+	struct ath11k_base *ab = ab_pci->ab;
+	int ret;
+
 	/* Do force MHI resume as some devices like QCA6390, WCN6855
 	 * are not in M3 state but they are functional. So just ignore
 	 * the MHI state while resuming.
 	 */
-	mhi_pm_resume_force(ab_pci->mhi_ctrl);
+	ret = mhi_pm_resume_force(ab_pci->mhi_ctrl);
+	if (ret) {
+		ath11k_warn(ab, "failed to resume mhi: %d", ret);
+		return ret;
+	}
+
+	return 0;
 }

drivers/net/wireless/ath/ath11k/mhi.h

@@ -23,7 +23,7 @@ void ath11k_mhi_unregister(struct ath11k_pci *ar_pci);
 void ath11k_mhi_set_mhictrl_reset(struct ath11k_base *ab);
 void ath11k_mhi_clear_vector(struct ath11k_base *ab);
 
-void ath11k_mhi_suspend(struct ath11k_pci *ar_pci);
-void ath11k_mhi_resume(struct ath11k_pci *ar_pci);
+int ath11k_mhi_suspend(struct ath11k_pci *ar_pci);
+int ath11k_mhi_resume(struct ath11k_pci *ar_pci);
 
 #endif

drivers/net/wireless/ath/ath11k/pci.c

@@ -619,18 +619,14 @@ static int ath11k_pci_hif_suspend(struct ath11k_base *ab)
 {
 	struct ath11k_pci *ar_pci = ath11k_pci_priv(ab);
 
-	ath11k_mhi_suspend(ar_pci);
-
-	return 0;
+	return ath11k_mhi_suspend(ar_pci);
 }
 
 static int ath11k_pci_hif_resume(struct ath11k_base *ab)
 {
 	struct ath11k_pci *ar_pci = ath11k_pci_priv(ab);
 
-	ath11k_mhi_resume(ar_pci);
-
-	return 0;
+	return ath11k_mhi_resume(ar_pci);
 }
 
 static void ath11k_pci_hif_ce_irq_enable(struct ath11k_base *ab)