Re: [PATCH net-next 7/7] wifi: mt76: move napi_enable() from under BH
From: Eric Dumazet <edumazet@google.com>
Date: 2025-01-22 14:25:59
Also in:
linux-wireless
On Tue, Jan 21, 2025 at 11:15 PM Jakub Kicinski [off-list ref] wrote:
mt76 does a lot of:
local_bh_disable();
napi_enable(...napi);
napi_schedule(...napi);
local_bh_enable();
local_bh_disable() is not a real lock, its most likely taken
because napi_schedule() requires it. napi_enable() needs
to take a mutex, so move it from under the BH protection.
Fixes: 413f0271f396 ("net: protect NAPI enablement with netdev_lock()")
Reported-by: Dan Carpenter <redacted>
Link: https://lore.kernel.org/dcfd56bc-de32-4b11-9e19-d8bd1543745d@stanley.mountain (local)
Signed-off-by: Jakub Kicinski <kuba@kernel.org>Reviewed-by: Eric Dumazet <edumazet@google.com> napi_schedule() can run from arbitrary contexts though... BH protection seems strange to me, but this is orthogonal to your fix.