From 08d52ba2967898723bf6fc57a9fb5dc0018cc5bc Mon Sep 17 00:00:00 2001 From: Kang Yang Date: Fri, 1 Dec 2023 18:09:47 +0200 Subject: [PATCH] wifi: ath12k: do not restore ASPM in case of single MSI vector Current code enables ASPM by default, it allows MHI to enter M2 state. In case of one MSI vector, system hang is observed if ath12k does MHI register reading in this state. The workaround here is to prevent MHI from entering M2 state, this can be done by disabling ASPM if only one MSI vector is used. When using 32 vectors ASPM is enabled as before. Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4 Signed-off-by: Kang Yang Acked-by: Jeff Johnson Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20231121021304.12966-7-quic_kangyang@quicinc.com --- drivers/net/wireless/ath/ath12k/pci.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath12k/pci.c b/drivers/net/wireless/ath/ath12k/pci.c index 32dcf91e0a06f..2d9ef7add95fa 100644 --- a/drivers/net/wireless/ath/ath12k/pci.c +++ b/drivers/net/wireless/ath/ath12k/pci.c @@ -1094,7 +1094,10 @@ int ath12k_pci_start(struct ath12k_base *ab) set_bit(ATH12K_PCI_FLAG_INIT_DONE, &ab_pci->flags); - ath12k_pci_aspm_restore(ab_pci); + if (test_bit(ATH12K_PCI_FLAG_MULTI_MSI_VECTORS, &ab_pci->flags)) + ath12k_pci_aspm_restore(ab_pci); + else + ath12k_info(ab, "leaving PCI ASPM disabled to avoid MHI M2 problems\n"); ath12k_pci_ce_irqs_enable(ab); ath12k_ce_rx_post_buf(ab); -- 2.30.2