On 02/28/2018 09:22 AM, David Miller wrote:
From: Jason Wang <[email protected]> Date: Wed, 28 Feb 2018 18:20:04 +0800We try to disable NAPI to prevent a single XDP TX queue being used by multiple cpus. But we don't check if device is up (NAPI is enabled), this could result stall because of infinite wait in napi_disable(). Fixing this by checking device state through netif_running() before. Fixes: 4941d472bf95b ("virtio-net: do not reset during XDP set") Signed-off-by: Jason Wang <[email protected]>Yes, mis-paired NAPI enable/disable are really a pain. Probably, we can do something in the interfaces or mechanisms to make this less error prone and less fragile. Anyways, applied and queued up for -stable, thanks!
I just hit a similar bug in ath10k. It seems like napi has plenty of free bit flags so it could keep track of 'is-enabled' state and allow someone to call napi_disable multiple times w/out deadlocking. Thanks, Ben -- Ben Greear <[email protected]> Candela Technologies Inc http://www.candelatech.com
