From: Alex Elder elder@linaro.org
commit 6c0e3b5ce94947b311348c367db9e11dcb2ccc93 upstream.
In ipa_endpoint_replenish(), if an error occurs when attempting to replenish a receive buffer, we just quit and try again later. In that case we increment the backlog count to reflect that the attempt was unsuccessful. Then, if the add_one flag was true we increment the backlog again.
This second increment is not included in the backlog local variable though, and its value determines whether delayed work should be scheduled. This is a bug.
Fix this by determining whether 1 or 2 should be added to the backlog before adding it in a atomic_add_return() call.
Reviewed-by: Matthias Kaehlcke mka@chromium.org Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints") Signed-off-by: Alex Elder elder@linaro.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ipa/ipa_endpoint.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
--- a/drivers/net/ipa/ipa_endpoint.c +++ b/drivers/net/ipa/ipa_endpoint.c @@ -918,10 +918,7 @@ static void ipa_endpoint_replenish(struc
try_again_later: /* The last one didn't succeed, so fix the backlog */ - backlog = atomic_inc_return(&endpoint->replenish_backlog); - - if (count) - atomic_add(count, &endpoint->replenish_backlog); + backlog = atomic_add_return(count + 1, &endpoint->replenish_backlog);
/* Whenever a receive buffer transaction completes we'll try to * replenish again. It's unlikely, but if we fail to supply even