Return-path: Received: from wolverine02.qualcomm.com ([199.106.114.251]:26665 "EHLO wolverine02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751398Ab2ADK1O (ORCPT ); Wed, 4 Jan 2012 05:27:14 -0500 From: Vasanthakumar Thiagarajan To: CC: , Subject: [PATCH] ath6kl: Use a mutex_lock to avoid race in diabling and handling irq Date: Wed, 4 Jan 2012 15:57:19 +0530 Message-ID: <1325672839-16608-1-git-send-email-vthiagar@qca.qualcomm.com> (sfid-20120104_112718_555433_DC5C3BE9) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: Currently this race is handled but in a messy way an atomic variable is being checked in a loop which sleeps upto ms in every iteration. Remove this logic and use a mutex to make sure irq is not disabled when irq handling is in progress. Signed-off-by: Vasanthakumar Thiagarajan --- drivers/net/wireless/ath/ath6kl/sdio.c | 19 +++++++++---------- 1 files changed, 9 insertions(+), 10 deletions(-) diff --git a/drivers/net/wireless/ath/ath6kl/sdio.c b/drivers/net/wireless/ath/ath6kl/sdio.c index 278a9f3..8b36904 100644 --- a/drivers/net/wireless/ath/ath6kl/sdio.c +++ b/drivers/net/wireless/ath/ath6kl/sdio.c @@ -49,11 +49,13 @@ struct ath6kl_sdio { /* scatter request list head */ struct list_head scat_req; + /* Avoids disabling irq while the interrupts being handled */ + struct mutex mtx_irq; + spinlock_t scat_lock; bool scatter_enabled; bool is_disabled; - atomic_t irq_handling; const struct sdio_device_id *id; struct work_struct wr_async_work; struct list_head wr_asyncq; @@ -460,8 +462,7 @@ static void ath6kl_sdio_irq_handler(struct sdio_func *func) ath6kl_dbg(ATH6KL_DBG_SDIO, "irq\n"); ar_sdio = sdio_get_drvdata(func); - atomic_set(&ar_sdio->irq_handling, 1); - + mutex_lock(&ar_sdio->mtx_irq); /* * Release the host during interrups so we can pick it back up when * we process commands. @@ -470,7 +471,7 @@ static void ath6kl_sdio_irq_handler(struct sdio_func *func) status = ath6kl_hif_intr_bh_handler(ar_sdio->ar); sdio_claim_host(ar_sdio->func); - atomic_set(&ar_sdio->irq_handling, 0); + mutex_unlock(&ar_sdio->mtx_irq); WARN_ON(status && status != -ECANCELED); } @@ -578,17 +579,14 @@ static void ath6kl_sdio_irq_disable(struct ath6kl *ar) sdio_claim_host(ar_sdio->func); - /* Mask our function IRQ */ - while (atomic_read(&ar_sdio->irq_handling)) { - sdio_release_host(ar_sdio->func); - schedule_timeout(HZ / 10); - sdio_claim_host(ar_sdio->func); - } + mutex_lock(&ar_sdio->mtx_irq); ret = sdio_release_irq(ar_sdio->func); if (ret) ath6kl_err("Failed to release sdio irq: %d\n", ret); + mutex_unlock(&ar_sdio->mtx_irq); + sdio_release_host(ar_sdio->func); } @@ -1253,6 +1251,7 @@ static int ath6kl_sdio_probe(struct sdio_func *func, spin_lock_init(&ar_sdio->scat_lock); spin_lock_init(&ar_sdio->wr_async_lock); mutex_init(&ar_sdio->dma_buffer_mutex); + mutex_init(&ar_sdio->mtx_irq); INIT_LIST_HEAD(&ar_sdio->scat_req); INIT_LIST_HEAD(&ar_sdio->bus_req_freeq); -- 1.7.0.4