Dear Marek, On 2016년 03월 25일 17:14, Marek Szyprowski wrote: > Dear Chanwoo, > > On 2016-03-25 01:10, Chanwoo Choi wrote: >> Hi Robert, >> >> I send following patch to fix the broken serial log of Exynos SoC. >> As I knew, you also knew this issue. >> If possible, could you review or test this patch? > > Robert no longer works for Samsung, so I'm afraid that he won't be able to > test > this patch.
Ah. Thanks for your reply. > >> Best Regards, >> Chanwoo Choi >> >> On 2016년 03월 14일 09:41, Chanwoo Choi wrote: >>> This patch fixes the broken serial log when changing the clock source >>> of uart device. Before disabling the original clock source, this patch >>> enables the new clock source to protect the clock off state for a split >>> second. >>> >>> Signed-off-by: Chanwoo Choi <[email protected]> >>> --- >>> drivers/tty/serial/samsung.c | 4 ++-- >>> 1 file changed, 2 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c >>> index d72cd736bdc6..80d59dbfebba 100644 >>> --- a/drivers/tty/serial/samsung.c >>> +++ b/drivers/tty/serial/samsung.c >>> @@ -1265,13 +1265,13 @@ static void s3c24xx_serial_set_termios(struct >>> uart_port *port, >>> if (ourport->baudclk != clk) { >>> s3c24xx_serial_setsource(port, clk_sel); >>> + clk_prepare_enable(clk); >>> + > > IMHO clk_prepare_enable() should be moved before s3c24xx_serial_setsource() > to be > really sure that there will be no period of hw operating with disabled baud > clock. > Could you check if it works for you? Yes. I tested it without any problem. But, as you commented, clk_prepare_enable() should be called before s3c24xx_serial_setsource(). I'll modify it. > >>> if (!IS_ERR(ourport->baudclk)) { >>> clk_disable_unprepare(ourport->baudclk); >>> ourport->baudclk = ERR_PTR(-EINVAL); >>> } >>> - clk_prepare_enable(clk); >>> - >>> ourport->baudclk = clk; >>> ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0; >>> } > > Best regards Best Regards, Chanwoo Choi
