Hi Arend,
2014-02-25 11:30 GMT-08:00 Arend van Spriel <arend@xxxxxxxxxxxx>:
> From: Hante Meuleman <meuleman@xxxxxxxxxxxx>
>
> The intstatus in sdio code can be updated from different
> threads. To protect intstatus access, atomic functions are
> used. One of them is set_bit, but this function is not
> guaranteed atomic on all platforms. The loop was replaced
> with local created OR function.
>
> Reviewed-by: Arend Van Spriel <arend@xxxxxxxxxxxx>
> Reviewed-by: Franky (Zhenhui) Lin <frankyl@xxxxxxxxxxxx>
> Reviewed-by: Pieter-Paul Giesberts <pieterpg@xxxxxxxxxxxx>
> Reviewed-by: Daniel (Deognyoun) Kim <dekim@xxxxxxxxxxxx>
> Signed-off-by: Hante Meuleman <meuleman@xxxxxxxxxxxx>
> Signed-off-by: Arend van Spriel <arend@xxxxxxxxxxxx>
> ---
> drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c | 29 ++++++++++----------
> 1 file changed, 15 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c b/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
> index ac61419..90ff406 100644
> --- a/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
> +++ b/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
> @@ -2444,12 +2444,21 @@ static inline void brcmf_sdio_clrintr(struct brcmf_sdio *bus)
> }
> }
>
> +static void atomic_orr(int val, atomic_t *v)
> +{
> + int old_val;
> +
> + old_val = atomic_read(v);
> + while (atomic_cmpxchg(v, old_val, val | old_val) != old_val)
> + old_val = atomic_read(v);
> +}
Is not atomic_set_mask() doing the same thing?
> +
> static int brcmf_sdio_intr_rstatus(struct brcmf_sdio *bus)
> {
> struct brcmf_core *buscore;
> u32 addr;
> unsigned long val;
> - int n, ret;
> + int ret;
>
> buscore = brcmf_chip_get_core(bus->ci, BCMA_CORE_SDIO_DEV);
> addr = buscore->base + offsetof(struct sdpcmd_regs, intstatus);
> @@ -2457,7 +2466,7 @@ static int brcmf_sdio_intr_rstatus(struct brcmf_sdio *bus)
> val = brcmf_sdiod_regrl(bus->sdiodev, addr, &ret);
> bus->sdcnt.f1regdata++;
> if (ret != 0)
> - val = 0;
> + return ret;
>
> val &= bus->hostintmask;
> atomic_set(&bus->fcstate, !!(val & I_HMB_FC_STATE));
> @@ -2466,13 +2475,7 @@ static int brcmf_sdio_intr_rstatus(struct brcmf_sdio *bus)
> if (val) {
> brcmf_sdiod_regwl(bus->sdiodev, addr, val, &ret);
> bus->sdcnt.f1regdata++;
> - }
> -
> - if (ret) {
> - atomic_set(&bus->intstatus, 0);
> - } else if (val) {
> - for_each_set_bit(n, &val, 32)
> - set_bit(n, (unsigned long *)&bus->intstatus.counter);
> + atomic_orr(val, &bus->intstatus);
> }
>
> return ret;
> @@ -2484,7 +2487,7 @@ static void brcmf_sdio_dpc(struct brcmf_sdio *bus)
> unsigned long intstatus;
> uint txlimit = bus->txbound; /* Tx frames to send before resched */
> uint framecnt; /* Temporary counter of tx/rx frames */
> - int err = 0, n;
> + int err = 0;
>
> brcmf_dbg(TRACE, "Enter\n");
>
> @@ -2588,10 +2591,8 @@ static void brcmf_sdio_dpc(struct brcmf_sdio *bus)
> }
>
> /* Keep still-pending events for next scheduling */
> - if (intstatus) {
> - for_each_set_bit(n, &intstatus, 32)
> - set_bit(n, (unsigned long *)&bus->intstatus.counter);
> - }
> + if (intstatus)
> + atomic_orr(intstatus, &bus->intstatus);
>
> brcmf_sdio_clrintr(bus);
>
> --
> 1.7.10.4
>
> --
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--
Florian
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