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: fa588eba63 ("net: Add Qcom WWAN control driver")
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Loic Poulain 2021-04-20 11:36:22 +02:00 committed by David S. Miller
parent 8f7e876273
commit a926c025d5

View file

@ -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))
if (test_bit(MHI_WWAN_RX_REFILL, &mhiwwan->flags))
ret = true;
}
spin_unlock(&mhiwwan->rx_lock);