From 69d03ee0b709a282f81e9f81c1359cffe1edcd2b Mon Sep 17 00:00:00 2001 From: Hante Meuleman Date: Sun, 25 Jan 2015 20:31:31 +0100 Subject: [PATCH] brcmfmac: prevent possible deadlock on resuming SDIO device. When the system is resumed a deadlock can occur when DPC gets entered before resume is complete. This patch fixes this by properly checking the suspend state outside the claim_host code block. 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: Kalle Valo --- .../net/wireless/brcm80211/brcmfmac/bcmsdh.c | 33 ------------------- .../net/wireless/brcm80211/brcmfmac/sdio.c | 18 ++++++++++ .../net/wireless/brcm80211/brcmfmac/sdio.h | 2 -- 3 files changed, 18 insertions(+), 35 deletions(-) diff --git a/drivers/net/wireless/brcm80211/brcmfmac/bcmsdh.c b/drivers/net/wireless/brcm80211/brcmfmac/bcmsdh.c index 00ba90b89455..8ba60f6f4915 100644 --- a/drivers/net/wireless/brcm80211/brcmfmac/bcmsdh.c +++ b/drivers/net/wireless/brcm80211/brcmfmac/bcmsdh.c @@ -97,25 +97,6 @@ static void brcmf_sdiod_dummy_irqhandler(struct sdio_func *func) { } -static bool brcmf_sdiod_pm_resume_error(struct brcmf_sdio_dev *sdiodev) -{ - bool is_err = false; -#ifdef CONFIG_PM_SLEEP - is_err = atomic_read(&sdiodev->suspend); -#endif - return is_err; -} - -static void brcmf_sdiod_pm_resume_wait(struct brcmf_sdio_dev *sdiodev, - wait_queue_head_t *wq) -{ -#ifdef CONFIG_PM_SLEEP - int retry = 0; - while (atomic_read(&sdiodev->suspend) && retry++ != 30) - wait_event_timeout(*wq, false, HZ/100); -#endif -} - int brcmf_sdiod_intr_register(struct brcmf_sdio_dev *sdiodev) { int ret = 0; @@ -244,10 +225,6 @@ static int brcmf_sdiod_request_data(struct brcmf_sdio_dev *sdiodev, u8 fn, brcmf_dbg(SDIO, "rw=%d, func=%d, addr=0x%05x, nbytes=%d\n", write, fn, addr, regsz); - brcmf_sdiod_pm_resume_wait(sdiodev, &sdiodev->request_word_wait); - if (brcmf_sdiod_pm_resume_error(sdiodev)) - return -EIO; - /* only allow byte access on F0 */ if (WARN_ON(regsz > 1 && !fn)) return -EINVAL; @@ -462,10 +439,6 @@ static int brcmf_sdiod_buffrw(struct brcmf_sdio_dev *sdiodev, uint fn, unsigned int req_sz; int err; - brcmf_sdiod_pm_resume_wait(sdiodev, &sdiodev->request_buffer_wait); - if (brcmf_sdiod_pm_resume_error(sdiodev)) - return -EIO; - /* Single skb use the standard mmc interface */ req_sz = pkt->len + 3; req_sz &= (uint)~3; @@ -516,10 +489,6 @@ static int brcmf_sdiod_sglist_rw(struct brcmf_sdio_dev *sdiodev, uint fn, if (!pktlist->qlen) return -EINVAL; - brcmf_sdiod_pm_resume_wait(sdiodev, &sdiodev->request_buffer_wait); - if (brcmf_sdiod_pm_resume_error(sdiodev)) - return -EIO; - target_list = pktlist; /* for host with broken sg support, prepare a page aligned list */ __skb_queue_head_init(&local_list); @@ -1077,8 +1046,6 @@ static int brcmf_ops_sdio_probe(struct sdio_func *func, #endif atomic_set(&sdiodev->suspend, false); - init_waitqueue_head(&sdiodev->request_word_wait); - init_waitqueue_head(&sdiodev->request_buffer_wait); brcmf_dbg(SDIO, "F2 found, calling brcmf_sdiod_probe...\n"); err = brcmf_sdiod_probe(sdiodev); diff --git a/drivers/net/wireless/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/brcm80211/brcmfmac/sdio.c index 99a37765888d..2c4f0ccd3b70 100644 --- a/drivers/net/wireless/brcm80211/brcmfmac/sdio.c +++ b/drivers/net/wireless/brcm80211/brcmfmac/sdio.c @@ -2609,6 +2609,21 @@ static int brcmf_sdio_intr_rstatus(struct brcmf_sdio *bus) return ret; } +static int brcmf_sdio_pm_resume_wait(struct brcmf_sdio_dev *sdiodev) +{ +#ifdef CONFIG_PM_SLEEP + int retry; + + /* Wait for possible resume to complete */ + retry = 0; + while ((atomic_read(&sdiodev->suspend)) && (retry++ != 50)) + msleep(20); + if (atomic_read(&sdiodev->suspend)) + return -EIO; +#endif + return 0; +} + static void brcmf_sdio_dpc(struct brcmf_sdio *bus) { u32 newstatus = 0; @@ -2619,6 +2634,9 @@ static void brcmf_sdio_dpc(struct brcmf_sdio *bus) brcmf_dbg(TRACE, "Enter\n"); + if (brcmf_sdio_pm_resume_wait(bus->sdiodev)) + return; + sdio_claim_host(bus->sdiodev->func[1]); /* If waiting for HTAVAIL, check status */ diff --git a/drivers/net/wireless/brcm80211/brcmfmac/sdio.h b/drivers/net/wireless/brcm80211/brcmfmac/sdio.h index 8eb42620129c..82494df541d4 100644 --- a/drivers/net/wireless/brcm80211/brcmfmac/sdio.h +++ b/drivers/net/wireless/brcm80211/brcmfmac/sdio.h @@ -169,8 +169,6 @@ struct brcmf_sdio_dev { u32 sbwad; /* Save backplane window address */ struct brcmf_sdio *bus; atomic_t suspend; /* suspend flag */ - wait_queue_head_t request_word_wait; - wait_queue_head_t request_buffer_wait; struct device *dev; struct brcmf_bus *bus_if; struct brcmfmac_sdio_platform_data *pdata; -- 2.20.1