qcacld: Fix of race condition leading to L2 errors

Fix of race condition between hif_pci_suspend and register
read from wlan_tasklet and sleep timer when PCIe link is
suspended and tis in D3 state.

Change-Id: I40037327a83e611865bb5d59ad7041200da30c77
CRs-Fixed: 665695

3 files changed, 16 insertions, 6 deletions

diff --git a/CORE/SERVICES/HIF/PCIe/hif_pci.c b/CORE/SERVICES/HIF/PCIe/hif_pci.c
index e4e739c54f3c..cf2e7f572e9a 100644
--- a/CORE/SERVICES/HIF/PCIe/hif_pci.c
+++ b/CORE/SERVICES/HIF/PCIe/hif_pci.c
@@ -2008,9 +2008,11 @@ HIF_sleep_entry(void *arg)
 		idle_ms = adf_os_ticks_to_msecs(adf_os_ticks()
 					- hif_state->sleep_ticks);
 		if (idle_ms >= HIF_MIN_SLEEP_INACTIVITY_TIME_MS) {
-			A_PCI_WRITE32(pci_addr + PCIE_LOCAL_BASE_ADDRESS +
+			if (!adf_os_atomic_read(&sc->pci_link_suspended)) {
+				A_PCI_WRITE32(pci_addr + PCIE_LOCAL_BASE_ADDRESS +
 				PCIE_SOC_WAKE_ADDRESS, PCIE_SOC_WAKE_RESET);
-			hif_state->fake_sleep = FALSE;
+				hif_state->fake_sleep = FALSE;
+			}
 		} else {
 			adf_os_timer_start(&hif_state->sleep_timer,
 				HIF_SLEEP_INACTIVITY_TIMER_PERIOD_MS);
diff --git a/CORE/SERVICES/HIF/PCIe/if_pci.c b/CORE/SERVICES/HIF/PCIe/if_pci.c
index 1d233a383994..747ed9bd3f61 100644
--- a/CORE/SERVICES/HIF/PCIe/if_pci.c
+++ b/CORE/SERVICES/HIF/PCIe/if_pci.c
@@ -613,7 +613,8 @@ wlan_tasklet(unsigned long data)
     }
 irq_handled:
     if (LEGACY_INTERRUPTS(sc) && (sc->ol_sc->target_status !=
-                                  OL_TRGET_STATUS_RESET)) {
+                                  OL_TRGET_STATUS_RESET) &&
+           (!adf_os_atomic_read(&sc->pci_link_suspended))) {
 
         if (sc->hif_init_done == TRUE)
             A_TARGET_ACCESS_BEGIN(hif_state->targid);
@@ -882,6 +883,7 @@ again:
     adf_os_atomic_init(&sc->tasklet_from_intr);
     adf_os_atomic_init(&sc->wow_done);
     adf_os_atomic_init(&sc->ce_suspend);
+    adf_os_atomic_init(&sc->pci_link_suspended);
     init_waitqueue_head(&ol_sc->sc_osdev->event_queue);
     init_completion(&ol_sc->ramdump_event);
 
@@ -1201,6 +1203,7 @@ again:
     adf_os_atomic_init(&sc->tasklet_from_intr);
     adf_os_atomic_init(&sc->wow_done);
     adf_os_atomic_init(&sc->ce_suspend);
+    adf_os_atomic_init(&sc->pci_link_suspended);
 
     init_waitqueue_head(&ol_sc->sc_osdev->event_queue);
     init_completion(&ol_sc->ramdump_event);
@@ -1713,9 +1716,6 @@ hif_pci_suspend(struct pci_dev *pdev, pm_message_t state)
         msleep(10);
     }
 
-    /* Stop the HIF Sleep Timer */
-    HIFCancelDeferredTargetSleep(sc->hif_device);
-
     /*Disable PCIe interrupts*/
     A_TARGET_ACCESS_BEGIN_RET(targid);
     A_PCI_WRITE32(sc->mem+(SOC_CORE_BASE_ADDRESS | PCIE_INTR_ENABLE_ADDRESS), 0);
@@ -1727,6 +1727,11 @@ hif_pci_suspend(struct pci_dev *pdev, pm_message_t state)
     }
     A_TARGET_ACCESS_END_RET(targid);
 
+    /* Stop the HIF Sleep Timer */
+    HIFCancelDeferredTargetSleep(sc->hif_device);
+
+    adf_os_atomic_set(&sc->pci_link_suspended, 1);
+
     pci_read_config_dword(pdev, OL_ATH_PCI_PM_CONTROL, &val);
     if ((val & 0x000000ff) != 0x3) {
         pci_save_state(pdev);
@@ -1751,6 +1756,8 @@ hif_pci_resume(struct pci_dev *pdev)
     v_VOID_t * temp_module;
     u32 tmp;
 
+    adf_os_atomic_set(&sc->pci_link_suspended, 0);
+
     /* Enable Legacy PCI line interrupts */
     A_TARGET_ACCESS_BEGIN_RET(targid);
     A_PCI_WRITE32(sc->mem+(SOC_CORE_BASE_ADDRESS | PCIE_INTR_ENABLE_ADDRESS),
diff --git a/CORE/SERVICES/HIF/PCIe/if_pci.h b/CORE/SERVICES/HIF/PCIe/if_pci.h
index 8114bc8b019b..a11ef830bea3 100644
--- a/CORE/SERVICES/HIF/PCIe/if_pci.h
+++ b/CORE/SERVICES/HIF/PCIe/if_pci.h
@@ -86,6 +86,7 @@ struct hif_pci_softc {
     atomic_t tasklet_from_intr;
     atomic_t wow_done;
     atomic_t ce_suspend;
+    atomic_t pci_link_suspended;
     bool hif_init_done;
     bool recovery;
     int htc_endpoint;