From 5cbb9c285bdcc14ee381120dab7e23a81060f1c0 Mon Sep 17 00:00:00 2001 From: Hante Meuleman Date: Thu, 6 Mar 2014 10:16:12 +0100 Subject: [PATCH] brcmfmac: Use atomic functions for intstatus update. 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 Reviewed-by: Franky (Zhenhui) Lin Reviewed-by: Pieter-Paul Giesberts Reviewed-by: Daniel (Deognyoun) Kim Signed-off-by: Hante Meuleman Signed-off-by: Arend van Spriel Signed-off-by: John W. Linville --- .../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 70bab5e089e..a111b6fbbeb 100644 --- a/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c +++ b/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c @@ -2439,12 +2439,21 @@ 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); +} + 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); @@ -2452,7 +2461,7 @@ 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)); @@ -2461,13 +2470,7 @@ 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; @@ -2479,7 +2482,7 @@ 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"); @@ -2583,10 +2586,8 @@ 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); -- 2.46.0