From 9a2a0862d973c9eab6a1f3efa0d4d18dcedbaf1a Mon Sep 17 00:00:00 2001 From: Wright Feng Date: Thu, 13 Aug 2020 02:00:16 -0500 Subject: brcmfmac: reserve tx credit only when txctl is ready to send The 4329 throughput drops from 40.2 Mbits/sec to 190 Kbits/sec in 2G 11n mode because the commit b41c232d33666 ("brcmfmac: reserve 2 credits for host tx control path"). To fix the issue, host driver only reserves tx control credit when there is a txctl frame is pending to send. And we also check available credit by using "not equal to 0" instead of "greater than 0" because tx_max and tx_seq are circled positive numbers. Reported-by: Dmitry Osipenko Fixes: b41c232d33666 ("brcmfmac: reserve 2 credits for host tx control path") Signed-off-by: Wright Feng Tested-by: Dmitry Osipenko Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20200813070017.89023-1-wright.feng@cypress.com --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c') diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c index e8712ad3ac45..3c07d1bbe1c6 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c @@ -664,9 +664,15 @@ static void pkt_align(struct sk_buff *p, int len, int align) /* To check if there's window offered */ static bool data_ok(struct brcmf_sdio *bus) { - /* Reserve TXCTL_CREDITS credits for txctl */ - return (bus->tx_max - bus->tx_seq) > TXCTL_CREDITS && - ((bus->tx_max - bus->tx_seq) & 0x80) == 0; + u8 tx_rsv = 0; + + /* Reserve TXCTL_CREDITS credits for txctl when it is ready to send */ + if (bus->ctrl_frame_stat) + tx_rsv = TXCTL_CREDITS; + + return (bus->tx_max - bus->tx_seq - tx_rsv) != 0 && + ((bus->tx_max - bus->tx_seq - tx_rsv) & 0x80) == 0; + } /* To check if there's window offered */ -- cgit v1.2.3