From: Ziyang Xuan <william.xuanziyang@huawei.com>
To: <chandrashekar.devegowda@intel.com>, <linuxwwan@intel.com>,
<chiranjeevi.rapolu@linux.intel.com>, <haijun.liu@mediatek.com>,
<m.chetan.kumar@linux.intel.com>,
<ricardo.martinez@linux.intel.com>, <loic.poulain@linaro.org>,
<ryazanov.s.a@gmail.com>, <johannes@sipsolutions.net>,
<davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
<pabeni@redhat.com>, <netdev@vger.kernel.org>
Subject: [PATCH net-next v2] net: wwan: t7xx: fix GFP_KERNEL usage in spin_lock context
Date: Tue, 17 May 2022 14:48:21 +0800 [thread overview]
Message-ID: <20220517064821.3966990-1-william.xuanziyang@huawei.com> (raw)
t7xx_cldma_clear_rxq() call t7xx_cldma_alloc_and_map_skb() in spin_lock
context, But __dev_alloc_skb() in t7xx_cldma_alloc_and_map_skb() uses
GFP_KERNEL, that will introduce scheduling factor in spin_lock context.
Because t7xx_cldma_clear_rxq() is called after stopping CLDMA, so we can
remove the spin_lock from t7xx_cldma_clear_rxq().
Fixes: 39d439047f1d ("net: wwan: t7xx: Add control DMA interface")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
---
drivers/net/wwan/t7xx/t7xx_hif_cldma.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wwan/t7xx/t7xx_hif_cldma.c b/drivers/net/wwan/t7xx/t7xx_hif_cldma.c
index 46066dcd2607..7493285a9606 100644
--- a/drivers/net/wwan/t7xx/t7xx_hif_cldma.c
+++ b/drivers/net/wwan/t7xx/t7xx_hif_cldma.c
@@ -782,10 +782,12 @@ static int t7xx_cldma_clear_rxq(struct cldma_ctrl *md_ctrl, int qnum)
struct cldma_queue *rxq = &md_ctrl->rxq[qnum];
struct cldma_request *req;
struct cldma_gpd *gpd;
- unsigned long flags;
int ret = 0;
- spin_lock_irqsave(&rxq->ring_lock, flags);
+ /* CLDMA has been stopped. There is not any CLDMA IRQ, holding
+ * ring_lock is not needed. Thus we can use functions that may
+ * introduce scheduling.
+ */
t7xx_cldma_q_reset(rxq);
list_for_each_entry(req, &rxq->tr_ring->gpd_ring, entry) {
gpd = req->gpd;
@@ -808,7 +810,6 @@ static int t7xx_cldma_clear_rxq(struct cldma_ctrl *md_ctrl, int qnum)
t7xx_cldma_gpd_set_data_ptr(req->gpd, req->mapped_buff);
}
- spin_unlock_irqrestore(&rxq->ring_lock, flags);
return ret;
}
--
2.25.1
next reply other threads:[~2022-05-17 6:31 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-17 6:48 Ziyang Xuan [this message]
2022-05-17 8:35 ` [PATCH net-next v2] net: wwan: t7xx: fix GFP_KERNEL usage in spin_lock context Sergey Ryazanov
2022-05-17 8:50 ` Loic Poulain
2022-05-18 4:39 ` Ziyang Xuan (William)
2022-05-18 18:09 ` Ilpo Järvinen
2022-05-19 4:20 ` Ziyang Xuan (William)
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