Abhishek Kumar [off-list ref] writes:

On Tue, Dec 15, 2020 at 9:24 AM Youghandhar Chintala
[off-list ref] wrote:

quoted

From: Rakesh Pillai <redacted>

Currently after the hardware restart triggered from the driver,
the station interface connection remains intact, since a disconnect
trigger is not sent to userspace. This can lead to a problem in
hardwares where the wifi mac sequence is added by the firmware.

After the firmware restart, during subsytem recovery, the firmware
restarts its wifi mac sequence number. Hence AP to which our device
is connected will receive frames with a  wifi mac sequence number jump
to the past, thereby resulting in the AP dropping all these frames,
until the frame arrives with a wifi mac sequence number which AP was
expecting.

To avoid such frame drops, its better to trigger a station disconnect
upon the  hardware restart. Indicate this support via a WIPHY flag
to mac80211, if the hardware params flag mentions the support to
add wifi mac sequence numbers for TX frames in the firmware.

All the other hardwares, except WCN3990, are not affected by this
change, since the hardware params flag is not set for any hardware
except for WCN3990

Tested-on: WCN3990 hw1.0 SNOC WLAN.HL.3.1-01040-QCAHLSWMTPLZ-1
Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00110-QCARMSWP-1
Tested-on: QCA6174 hw3.2 SDIO WLAN.RMH.4.4.1-00048

Signed-off-by: Rakesh Pillai <redacted>
Signed-off-by: Youghandhar Chintala <redacted>
---
 drivers/net/wireless/ath/ath10k/core.c | 15 +++++++++++++++
 drivers/net/wireless/ath/ath10k/hw.h   |  3 +++
 drivers/net/wireless/ath/ath10k/mac.c  |  3 +++
 3 files changed, 21 insertions(+)

diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
index 796107b..4155f94 100644
--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c

@@ -90,6 +90,7 @@ static const struct ath10k_hw_params ath10k_hw_params_list[] = {
                .hw_filter_reset_required = true,
                .fw_diag_ce_download = false,
                .tx_stats_over_pktlog = true,
+               .tx_mac_seq_by_fw = false,

Probably orthogonal to this patch, there is a static array maintained
for different hardware configs and the structure members like
"tx_mac_seq_by_fw" are initialized. This does not seem to be scalable
and probably these parameters can be auto populated based on FW
capabilities and so we don't have to maintain the static array.
Thoughts?

I'm not sure what you mean. But if you are saying that we should move
ath10k_hw_params_list entirely to firmware then that is a huge task as
we would need to make changes in every firmware branch, and there are so
many different branches that I have lost count. And due to backwards
compatibility we still need to have ath10k_hw_params_list in ath10k for
few years.

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