From: Wen Gong wgong@codeaurora.org
[ Upstream commit 2fd3c8f34d08af0a6236085f9961866ad92ef9ec ]
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@codeaurora.org Signed-off-by: Kalle Valo kvalo@codeaurora.org Link: https://lore.kernel.org/r/20200108031957.22308-3-wgong@codeaurora.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/ath/ath10k/sdio.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c index fef313099e08a..34e8b4344f40a 100644 --- a/drivers/net/wireless/ath/ath10k/sdio.c +++ b/drivers/net/wireless/ath/ath10k/sdio.c @@ -561,6 +561,10 @@ static int ath10k_sdio_mbox_rx_alloc(struct ath10k *ar, le16_to_cpu(htc_hdr->len), ATH10K_HTC_MBOX_MAX_PAYLOAD_LENGTH); ret = -ENOMEM; + + queue_work(ar->workqueue, &ar->restart_work); + ath10k_warn(ar, "exceeds length, start recovery\n"); + goto err; }