[PATCH] riscv/console: Updated the console-config.c file

Hesham Almatary hesham.almatary at cl.cam.ac.uk
Fri Apr 30 12:18:18 UTC 2021


On Fri, 30 Apr 2021 at 04:44, somesh deshmukh <someshdeshmukh07 at gmail.com>
wrote:

>
>
> On Thu, Apr 29, 2021 at 10:59 PM Hesham Almatary <
> hesham.almatary at cl.cam.ac.uk> wrote:
>
>> On Wed, 28 Apr 2021 at 15:23, Somesh Deshmukh
>> <someshdeshmukh07 at gmail.com> wrote:
>> >
>> > - Parsing the sub-node should be available generic not specific to
>> Freedom
>> >   Arty310 board. If we remove the Freedom Arty macro now, it will lose
>> >   backward compatibility.The proposed change will retain the backward
>> >   compatibility and also adds the necessary fix for parsing sub-node.
>> >
>> > - Line 234 and 235 in riscv_console_probe() uses polled handlers for
>> ns16550
>> >   read and write while, the console_initialize function uses ns16550
>> >   interrupt handler. Proposing a fix to make polled handlers consistant
>> >   through out the console-config.c
>> > ---
>> >  bsps/riscv/riscv/console/console-config.c | 4 ++--
>> >  1 file changed, 2 insertions(+), 2 deletions(-)
>> >
>> > diff --git a/bsps/riscv/riscv/console/console-config.c
>> b/bsps/riscv/riscv/console/console-config.c
>> > index d962a5a418..f203f0be7d 100644
>> > --- a/bsps/riscv/riscv/console/console-config.c
>> > +++ b/bsps/riscv/riscv/console/console-config.c
>> > @@ -91,7 +91,7 @@ static int riscv_get_console_node(const void *fdt)
>> >      stdout_path = "";
>> >    }
>> >
>> > -#if RISCV_ENABLE_FRDME310ARTY_SUPPORT != 0
>> > +#if ((RISCV_ENABLE_FRDME310ARTY_SUPPORT != 0) ||
>> (RISCV_CONSOLE_MAX_NS16550_DEVICES > 0))
>> >    int root;
>> >    int soc;
>> >    root = fdt_path_offset(fdt, "/");
>> > @@ -318,7 +318,7 @@ rtems_status_code console_initialize(
>> >
>> >      rtems_termios_device_install(
>> >        path,
>> > -      &ns16550_handler_interrupt,
>> > +      &ns16550_handler_polled,
>> I would leave the driver interrupt-based as it is. Other than that the
>> patch is fine by me.
>>
>> Thanks Hesham for the review.
> One question though, is there any specific reason to use the
> ns16550_handler_interrupt?
>
Interrupt-based drivers are preferred as they don’t unnecessarily waste CPU
cycles and power.

>
> >        NULL,
>
> >        &ctx->base
>> >      );
>> > --
>> > 2.25.1
>> >
>> > _______________________________________________
>> > devel mailing list
>> > devel at rtems.org
>> > http://lists.rtems.org/mailman/listinfo/devel
>>
>
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