Wen Gong <wgong@xxxxxxxxxxxxxx> wrote: > When simulate random transfer fail for sdio write and read, it happened > "payload length exceeds max htc length" and recovery later sometimes. > > Test steps: > 1. Add config and update kernel: > CONFIG_FAIL_MMC_REQUEST=y > CONFIG_FAULT_INJECTION=y > CONFIG_FAULT_INJECTION_DEBUG_FS=y > > 2. Run simulate fail: > cd /sys/kernel/debug/mmc1/fail_mmc_request > echo 10 > probability > echo 10 > times # repeat until hitting issues > > 3. It happened payload length exceeds max htc length. > [ 199.935506] ath10k_sdio mmc1:0001:1: payload length 57005 exceeds max htc length: 4088 > .... > [ 264.990191] ath10k_sdio mmc1:0001:1: payload length 57005 exceeds max htc length: 4088 > > 4. after some time, such as 60 seconds, it start recovery which triggered > by wmi command timeout for periodic scan. > [ 269.229232] ieee80211 phy0: Hardware restart was requested > [ 269.734693] ath10k_sdio mmc1:0001:1: device successfully recovered > > The simulate fail of sdio is not a real sdio transter fail, it only > set an error status in mmc_should_fail_request after the transfer end, > actually the transfer is success, then sdio_io_rw_ext_helper will > return error status and stop transfer the left data. For example, > the really RX len is 286 bytes, then it will split to 2 blocks in > sdio_io_rw_ext_helper, one is 256 bytes, left is 30 bytes, if the > first 256 bytes get an error status by mmc_should_fail_request,then > the left 30 bytes will not read in this RX operation. Then when the > next RX arrive, the left 30 bytes will be considered as the header > of the read, the top 4 bytes of the 30 bytes will be considered as > lookaheads, but actually the 4 bytes is not the lookaheads, so the len > from this lookaheads is not correct, it exceeds max htc length 4088 > sometimes. When happened exceeds, the buffer chain is not matched between > firmware and ath10k, then it need to start recovery ASAP. Recently then > recovery will be started by wmi command timeout, but it will be long time > later, for example, it is 60+ seconds later from the periodic scan, if > it does not have periodic scan, it will be longer. > > Start recovery when it happened "payload length exceeds max htc length" > will be reasonable. > > This patch only effect sdio chips. > > Tested with QCA6174 SDIO with firmware WLAN.RMH.4.4.1-00029. > > Signed-off-by: Wen Gong <wgong@xxxxxxxxxxxxxx> > Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx> Patch applied to ath-next branch of ath.git, thanks. 2fd3c8f34d08 ath10k: start recovery process when payload length exceeds max htc length for sdio -- https://patchwork.kernel.org/patch/11322583/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
