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authorJonas Dreßler <verdre@v0yd.nl>2021-10-11 15:32:23 +0200
committerKalle Valo <kvalo@codeaurora.org>2021-10-18 15:29:51 +0300
commite5f4eb8223aa740237cd463246a7debcddf4eda1 (patch)
tree7e88fde9a1a94a975ed5c7d6a34689720c4ea41f /drivers/net/wireless/marvell/mwifiex/pcie.c
parentwireless: Remove redundant 'flush_workqueue()' calls (diff)
downloadlinux-dev-e5f4eb8223aa740237cd463246a7debcddf4eda1.tar.xz
linux-dev-e5f4eb8223aa740237cd463246a7debcddf4eda1.zip
mwifiex: Read a PCI register after writing the TX ring write pointer
On the 88W8897 PCIe+USB card the firmware randomly crashes after setting the TX ring write pointer. The issue is present in the latest firmware version 15.68.19.p21 of the PCIe+USB card. Those firmware crashes can be worked around by reading any PCI register of the card after setting that register, so read the PCI_VENDOR_ID register here. The reason this works is probably because we keep the bus from entering an ASPM state for a bit longer, because that's what causes the cards firmware to crash. This fixes a bug where during RX/TX traffic and with ASPM L1 substates enabled (the specific substates where the issue happens appear to be platform dependent), the firmware crashes and eventually a command timeout appears in the logs. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=109681 Cc: stable@vger.kernel.org Signed-off-by: Jonas Dreßler <verdre@v0yd.nl> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Link: https://lore.kernel.org/r/20211011133224.15561-2-verdre@v0yd.nl
Diffstat (limited to 'drivers/net/wireless/marvell/mwifiex/pcie.c')
-rw-r--r--drivers/net/wireless/marvell/mwifiex/pcie.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.c b/drivers/net/wireless/marvell/mwifiex/pcie.c
index c6ccce426b49..641fa539de1f 100644
--- a/drivers/net/wireless/marvell/mwifiex/pcie.c
+++ b/drivers/net/wireless/marvell/mwifiex/pcie.c
@@ -1490,6 +1490,14 @@ mwifiex_pcie_send_data(struct mwifiex_adapter *adapter, struct sk_buff *skb,
ret = -1;
goto done_unmap;
}
+
+ /* The firmware (latest version 15.68.19.p21) of the 88W8897 PCIe+USB card
+ * seems to crash randomly after setting the TX ring write pointer when
+ * ASPM powersaving is enabled. A workaround seems to be keeping the bus
+ * busy by reading a random register afterwards.
+ */
+ mwifiex_read_reg(adapter, PCI_VENDOR_ID, &rx_val);
+
if ((mwifiex_pcie_txbd_not_full(card)) &&
tx_param->next_pkt_len) {
/* have more packets and TxBD still can hold more */