can: mcp251x: Move to threaded interrupts instead of workqueues.
can: mcp251x: Move to threaded interrupts instead of workqueues.

This patch addresses concerns about efficiency of handling incoming
packets. Handling of interrupts is done in a threaded interrupt handler
which has a smaller latency than workqueues. This change needed a rework
of the locking scheme that was much simplified. Some other (more or less
longstanding) bugs are fixed: utilization of just half of the RX
buffers, useless wait for interrupt on open, more reliable reset
sequence. The MERR interrupt is not used anymore: it overloads the CPU
in error-passive state without any additional information. One shot mode
is disabled because it's not clear if it can be handled efficiently on
this CAN controller.

Signed-off-by: Christian Pellegrin <4987a418c2e68aa71fe786aa3bd683ef5826507d@fsfe.org>
Acked-by: Wolfgang Grandegger <5aa1976eca1fee4e35c7b71ec8e8a0ebad9da3d1@grandegger.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs