net: phy: smsc: Cache interrupt mask

Cache the interrupt mask to avoid re-reading it from the PHY upon every
interrupt.

This will simplify a subsequent commit which detects hot-removal in the
interrupt handler and bails out.

Analyzing and debugging PHY transactions also becomes simpler if such
redundant reads are avoided.

Last not least, interrupt overhead and latency is slightly improved.

Tested-by: Oleksij Rempel <[email protected]> # LAN9514/9512/9500
Tested-by: Ferry Toth <[email protected]> # LAN9514
Signed-off-by: Lukas Wunner <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions