tree dc5cbed1c88862a843971b1e7da0a0ebe6493911
parent 3be7988674ab33565700a37b210f502563d932e6
author Yadi.hu <yadi.hu@windriver.com> 1474195951 +0800
committer Wolfram Sang <wsa@the-dreams.de> 1474474071 +0200

i2c-eg20t: fix race between i2c init and interrupt enable

the eg20t driver call request_irq() function before the pch_base_address,
base address of i2c controller's register, is assigned an effective value.

there is one possible scenario that an interrupt which isn't inside eg20t
arrives immediately after request_irq() is executed when i2c controller
shares an interrupt number with others. since the interrupt handler
pch_i2c_handler() has already active as shared action, it will be called
and read its own register to determine if this interrupt is from itself.

At that moment, since base address of i2c registers is not remapped
in kernel space yet,so the INT handler will access an illegal address
and then a error occurs.

Signed-off-by: Yadi.hu <yadi.hu@windriver.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org