From: Loic Poulain Date: Tue, 20 Apr 2021 09:36:22 +0000 (+0200) Subject: net: wwan: mhi_wwan_ctrl: Fix RX buffer starvation X-Git-Tag: v5.13-rc1~94^2~78 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a926c025d56bb1acd8a192fca0e307331ee91b30;p=thirdparty%2Fkernel%2Flinux.git net: wwan: mhi_wwan_ctrl: Fix RX buffer starvation The mhi_wwan_rx_budget_dec function is supposed to return true if RX buffer budget has been successfully decremented, allowing to queue a new RX buffer for transfer. However the current implementation is broken when RX budget is '1', in which case budget is decremented but false is returned, preventing to requeue one buffer, and leading to RX buffer starvation. Fixes: fa588eba632d ("net: Add Qcom WWAN control driver") Signed-off-by: Loic Poulain Signed-off-by: David S. Miller --- diff --git a/drivers/net/wwan/mhi_wwan_ctrl.c b/drivers/net/wwan/mhi_wwan_ctrl.c index 416ae6abafb76..1bc6b69aa5302 100644 --- a/drivers/net/wwan/mhi_wwan_ctrl.c +++ b/drivers/net/wwan/mhi_wwan_ctrl.c @@ -58,11 +58,11 @@ static bool mhi_wwan_rx_budget_dec(struct mhi_wwan_dev *mhiwwan) spin_lock(&mhiwwan->rx_lock); - if (mhiwwan->rx_budget) + if (mhiwwan->rx_budget) { mhiwwan->rx_budget--; - - if (mhiwwan->rx_budget && test_bit(MHI_WWAN_RX_REFILL, &mhiwwan->flags)) - ret = true; + if (test_bit(MHI_WWAN_RX_REFILL, &mhiwwan->flags)) + ret = true; + } spin_unlock(&mhiwwan->rx_lock);