On Wed, Aug 9, 2023 at 2:27 PM Baolin Wang
<baolin.wang@xxxxxxxxxxxxxxxxx> wrote:
>
>
>
> On 8/9/2023 1:52 PM, wenhua lin wrote:
> > The change of the max ports is to adapt to an new
> > SPRD serial hardware,also is backward-compatibility with old hardware.
>
> Again, DO NOT top-posting! Thanks.
Thank you for your correction.
>
> >>
> >> On 8/7/2023 4:07 PM, Wenhua Lin wrote:
> >>> From: Wenhua Lin <wenhua.lin@xxxxxxxxxx>
> >>>
> >>> Support 12 uart ports, which can solve the problem
> >>> of insufficient uart ports.
> >>
> >> This sounds incorrect to me.
> >> If this is a software bug, please add a Fixes tag to backport for stable
> >> kernels. If the change of the max ports is only avaliable on the new
> >> SPRD serial hardware, you should ensure the change is
> >> backward-compatibility with old hardware.
>
> This is not backward-compatibility. Please see 'sprd_uart_driver'
> structure as below:
>
> static struct uart_driver sprd_uart_driver = {
> .owner = THIS_MODULE,
> .driver_name = "sprd_serial",
> .dev_name = SPRD_TTY_NAME,
> .major = 0,
> .minor = 0,
> .nr = UART_NR_MAX,
> .cons = SPRD_CONSOLE,
> };
>
> That means you will still register 12 UART ports in the tty for old
> serial hardwares which actually only support 8 UART ports, and if users
> want to use another 4 ports which are not supported in the hardware,
> then system crashes.
>
> So I think you should add a SoC data in 'serial_ids' to change the
> number of UART port according to different SoC.
>
Thank you for your valuable comments, we should probably consider
how to make changes based on your suggestions.
> >>> Signed-off-by: Wenhua Lin <wenhua.lin@xxxxxxxxxx>
> >>> ---
> >>> drivers/tty/serial/sprd_serial.c | 2 +-
> >>> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>>
> >>> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
> >>> index b58f51296ace..2774df490899 100644
> >>> --- a/drivers/tty/serial/sprd_serial.c
> >>> +++ b/drivers/tty/serial/sprd_serial.c
> >>> @@ -22,7 +22,7 @@
> >>> #include <linux/tty_flip.h>
> >>>
> >>> /* device name */
> >>> -#define UART_NR_MAX 8
> >>> +#define UART_NR_MAX 12
> >>> #define SPRD_TTY_NAME "ttyS"
> >>> #define SPRD_FIFO_SIZE 128
> >>> #define SPRD_DEF_RATE 26000000
