Chi-Hsien Lin <chi-hsien.lin@xxxxxxxxxxx> writes:
> From: Amar Shankar <amsr@xxxxxxxxxxx>
>
> It is observed that sometimes when sdiod is low in tx credits in low
> rssi scenarios, the data path consumes all sdiod rx all credits and
> there is no sdiod rx credit available for control path causing host
> and card to go out of sync resulting in link loss between host and
> card. So in order to prevent it some credits are reserved for control
> path.
>
> Note that TXCTL_CREDITS can't be larger than the firmware default
> credit update threshold 2; otherwise there will be a deadlock for both
> side waiting for each other.
>
> Signed-off-by: Amar Shankar <amsr@xxxxxxxxxxx>
> Signed-off-by: Jia-Shyr Chuang <saint.chuang@xxxxxxxxxxx>
> Signed-off-by: Chi-Hsien Lin <chi-hsien.lin@xxxxxxxxxxx>
> ---
> .../wireless/broadcom/brcm80211/brcmfmac/sdio.c | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
> index ce6f15284277..163bb7f41e44 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
> @@ -635,6 +635,8 @@ static const struct brcmf_firmware_mapping brcmf_sdio_fwnames[] = {
> BRCMF_FW_ENTRY(CY_CC_43012_CHIP_ID, 0xFFFFFFFF, 43012)
> };
>
> +#define TXCTL_CREDITS 2
> +
> static void pkt_align(struct sk_buff *p, int len, int align)
> {
> uint datalign;
> @@ -647,6 +649,14 @@ 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 (u8)(bus->tx_max - bus->tx_seq) > TXCTL_CREDITS &&
> + ((u8)(bus->tx_max - bus->tx_seq) & 0x80) == 0;
> +}
Why casting to u8? Is it really necessary?
--
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
