serial: sh-sci: Fix panic when serial console and DMA are enabled
authorTakatoshi Akiyama <takatoshi.akiyama.kj@ps.hitachi-solutions.com>
Mon, 27 Feb 2017 06:56:31 +0000 (15:56 +0900)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 14 Mar 2017 02:59:04 +0000 (10:59 +0800)
commit3c9101766b502a0163d1d437fada5801cf616be2
tree7425bab15a23f264d748c841e583a3ae2a74a438
parent713b93f1b849527e8c440753fc92cc6c202f2092
serial: sh-sci: Fix panic when serial console and DMA are enabled

This patch fixes an issue that kernel panic happens when DMA is enabled
and we press enter key while the kernel booting on the serial console.

* An interrupt may occur after sci_request_irq().
* DMA transfer area is initialized by setup_timer() in sci_request_dma()
  and used in interrupt.

If an interrupt occurred between sci_request_irq() and setup_timer() in
sci_request_dma(), DMA transfer area has not been initialized yet.
So, this patch changes the order of sci_request_irq() and
sci_request_dma().

Fixes: 73a19e4c0301 ("serial: sh-sci: Add DMA support.")
Signed-off-by: Takatoshi Akiyama <takatoshi.akiyama.kj@ps.hitachi-solutions.com>
[Shimoda changes the commit log]
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/sh-sci.c