| Message ID | 20210421035616.14540-1-jarvis.w.jiang@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v1] net: Qcom WWAN control driver: fix the rx_budget was eaten incorrectly | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Guessing tree name failed - patch did not apply |
Hi Jarvis, On Wed, 21 Apr 2021 at 05:57, Jarvis Jiang <jarvis.w.jiang@gmail.com> wrote: > > mhi_wwan_rx_budget_dec() should check the value of mhiwwan->rx_budget > before the decrement, not the value after decrement. > > When mhiwwan->rx_budget = 1, mhi_wwan_rx_budget_dec() will always return > false, which will cause the mhi_wwan_ctrl_refill_work() not to queue rx > buffers to transfer ring any more, and rx will be stuck. > > This patch was tested with Ubuntu 20.04 X86_64 PC as host > > Signed-off-by: Jarvis Jiang <jarvis.w.jiang@gmail.com> Thanks for the patch, but a similar change for this issue has just been merged in net-next (a926c025d56b net: wwan: mhi_wwan_ctrl: Fix RX buffer starvation). Regards, Loic
diff --git a/drivers/net/wwan/mhi_wwan_ctrl.c b/drivers/net/wwan/mhi_wwan_ctrl.c index 11475ade4be5..721edf5a238f 100644 --- a/drivers/net/wwan/mhi_wwan_ctrl.c +++ b/drivers/net/wwan/mhi_wwan_ctrl.c @@ -56,12 +56,12 @@ static bool mhi_wwan_rx_budget_dec(struct mhi_wwan_dev *mhiwwan) spin_lock(&mhiwwan->rx_lock); - if (mhiwwan->rx_budget) - mhiwwan->rx_budget--; - if (mhiwwan->rx_budget && test_bit(MHI_WWAN_RX_REFILL, &mhiwwan->flags)) ret = true; + if (mhiwwan->rx_budget) + mhiwwan->rx_budget--; + spin_unlock(&mhiwwan->rx_lock); return ret;
mhi_wwan_rx_budget_dec() should check the value of mhiwwan->rx_budget before the decrement, not the value after decrement. When mhiwwan->rx_budget = 1, mhi_wwan_rx_budget_dec() will always return false, which will cause the mhi_wwan_ctrl_refill_work() not to queue rx buffers to transfer ring any more, and rx will be stuck. This patch was tested with Ubuntu 20.04 X86_64 PC as host Signed-off-by: Jarvis Jiang <jarvis.w.jiang@gmail.com> --- drivers/net/wwan/mhi_wwan_ctrl.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)