On 2019/12/5 20:39, Jiri Slaby wrote: > On 05. 12. 19, 13:30, Xiongfeng Wang wrote: >> >> >> On 2019/12/5 20:13, Greg KH wrote: >>> On Thu, Dec 05, 2019 at 08:04:36PM +0800, Xiongfeng Wang wrote: >>>> Fix the following warning: >>>> drivers/tty/serial/omap-serial.c: In function serial_omap_rlsi: >>>> drivers/tty/serial/omap-serial.c:496:16: warning: variable ch set but not used [-Wunused-but-set-variable] >>>> >>>> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx> >>>> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx> >>>> --- >>>> drivers/tty/serial/omap-serial.c | 3 +-- >>>> 1 file changed, 1 insertion(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c >>>> index 6420ae5..54ee3ae 100644 >>>> --- a/drivers/tty/serial/omap-serial.c >>>> +++ b/drivers/tty/serial/omap-serial.c >>>> @@ -493,10 +493,9 @@ static unsigned int check_modem_status(struct uart_omap_port *up) >>>> static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr) >>>> { >>>> unsigned int flag; >>>> - unsigned char ch = 0; >>>> >>>> if (likely(lsr & UART_LSR_DR)) >>>> - ch = serial_in(up, UART_RX); >>>> + serial_in(up, UART_RX); >>> >>> Shouldn't you be doing something with 'ch'? >> >> Sorry, my original thought is trying not to modify the existing logic. >> I will look into the mechanism to see if I need to check 'ch'. > > The change looks in fact correct, see: > commit 9a12fcf8b1543c99ffcec3d61db86f0dea52dc9d > Author: Shubhrajyoti D <shubhrajyoti@xxxxxx> > Date: Fri Sep 21 20:07:19 2012 +0530 > > serial: omap: fix the reciever line error case > > It also says: "This is recommended in the interrupt reset method in the > table 23-246 of the omap4 TRM." > > The character read is erroneous and should be apparently dropped. But > you should add a comment about it, though. Thanks a lot. I will add it in the comment and send another version. Thanks, Xiongfeng > > thanks, >