Bug 83131

Summary: can: ti_hecc.c: closing device while receiving can messages, effectively disables all socket transfer
Product: Networking Reporter: jan.sondhauss
Component: OtherAssignee: Stephen Hemminger (stephen)
Status: NEW ---    
Severity: normal    
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 3.16.1 Subsystem:
Regression: No Bisected commit-id:
Attachments: Patch file removing the early return in case the device is closed already

Description jan.sondhauss 2014-08-24 13:07:41 UTC 
drivers/net/can/ti_hecc.c:

When closing the can device, its not ensured that it gets removed from the socket-poll list.

The problem here lies in the ti_hecc_rx_poll() function which returns early when the device is closed already.
This leads to napi_complete() never being called, thus the device stays in the napi's poll list forever and every task reading from any socket is polling this device. The system is now basically unreachable.

The patch attached seams to fix this problem by removing the early return in the ti_hecc_rx_poll function. But I'm not sure whether this is the correct solution.
Comment 1 jan.sondhauss 2014-08-24 13:08:47 UTC 
Created attachment 147921 [details]
Patch file removing the early return in case the device is closed already