mac80211: ath12k: prevent ltssm crash

Fix ltssm crashes on BPI-Rx boards.
Seems read32/write32 using wrong address which
is not a problem on x86/64 PCI controllers.
But have issues on BPI-Rx boards.

Signed-off-by: Janusz Dziedzic <janusz.dziedzic@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/15945
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

diff --git a/package/kernel/mac80211/patches/ath12k/100-ath12k-prevent-ltssm-startup-crash.patch b/package/kernel/mac80211/patches/ath12k/100-ath12k-prevent-ltssm-startup-crash.patch
new file mode 100644 (file)
index 0000000..cd85a0f
--- /dev/null
+++ b/package/kernel/mac80211/patches/ath12k/100-ath12k-prevent-ltssm-startup-crash.patch
@@ -0,0 +1,17 @@
+Fix ltssm crashes on BPI-Rx boards.
+Seems read32/write32 using wrong address which
+is not a problem on x86/64 PCI controllers.
+But have issues on BPI-Rx boards.
+
+--- a/drivers/net/wireless/ath/ath12k/pci.c
++++ b/drivers/net/wireless/ath/ath12k/pci.c
+@@ -277,6 +277,9 @@ static void ath12k_pci_enable_ltssm(stru
+       u32 val;
+       int i;
+ 
++      /* Prevent startup crash on BPI-Rx */
++      return;
++
+       val = ath12k_pci_read32(ab, PCIE_PCIE_PARF_LTSSM);
+ 
+       /* PCIE link seems very unstable after the Hot Reset*/