Re: [PATCH, new ACPI driver] new sony_acpi driver

Stelian Pop
2005-02-11T11:15:58Z

On Fri, Feb 11, 2005 at 11:30:35AM +0100, Jean Delvare wrote:

> Hi Stelian, all,
>
> >This driver has been submitted (almost unchanged) on lkml and
> >on acpi-devel twice, first on July 21, 2004, then again on
> >September 17, 2004. It has been quietly ignored.
> >
> >Privately I've had many positive feedbacks from users of this driver
> >(and no negative feedback), including Linux distributions who wish
> >to include it into their kernels. The reports are increasing in number,
> >it would seem that newer Sony Vaios are more and more incompatible
> >with sonypi and require sony_acpi to control the screen brightness.
>
> I'm sorry I missed the first two announcements. I'll give a try to your
> driver this evening, and report how it is working for me.

thanks.

> In the meantime, I'd have some comments on your patch:
>
> >+static int debug = 0;

> No need to initialize it to 0, the compiler does it for you (and more
> efficiently at that).

sure.
>
> >+module_param(debug, int, 0);
> >+MODULE_PARM_DESC(debug,"set this to 1 (and RTFM) if you want to help the
> >development of this driver");
>
> Lack of space after comma, and line too long, split it please.

done.

> >+static struct acpi_driver sony_acpi_driver = {
> >+ name: ACPI_SNC_DRIVER_NAME,
> >+ class: ACPI_SNC_CLASS,
> >+ ids: ACPI_SNC_HID,
> >+ ops: {
> >+ add: sony_acpi_add,
> >+ remove: sony_acpi_remove,
> >+ },
> >+};
>
> As far as I know, you are supposed to use C99-style for structure
> initialization:
> .name = ACPI_SNC_DRIVER_NAME,
> etc.

of course.

> >+ printk(KERN_WARNING "acpi_callreadfunc failed\n");
>
> Please prepend the driver name before such messages (everywhere in the
> driver). It's annoying when you see error messages in your logs and
> don't know which driver caused them.

done.

> >+static int parse_buffer(const char __user *buffer, unsigned long count,
> >int *val) {
> >+ char s[32];
> >+
> >+ if (count > 31)
> >+ return -EINVAL;
> >+ if (copy_from_user(s, buffer, count))
> >+ return -EFAULT;
> >+ s[count] = 0;
>
> = '\0' would look better IMHO.
>
> >+ if (sscanf(s, "%i", val) != 1)
>
> Can't you use simple_strtoul instead? This would be more efficient, or
> so I guess.

Indeed, sscanf calls simple_strtoul.

>
> >--- /dev/null 2005-02-10 10:35:32.824183288 +0100
> >+++ linux-2.6-stelian/Documentation/sony_acpi.txt 2005-01-31
> >17:00:09.000000000 +0100
>
> Could be the time to create a Documentation/acpi directory and start
> populating it. It's odd that such a large subsystem has no documentation
> in the kernel tree.

I agree. Let's see if the acpi people follow :)

> >+You should start by trying the sonypi driver, which does
> >+all this and many other things. But the sonypi driver does
> >+not work on all sonypi laptops, whereas sony_acpi should
> >+work everywhere.
>
> s/all sonypi laptops/all Sony laptops/?

doh :)

> >+Loading the sony_acpi.ko module will create a /proc/acpi/sony/
> >+directory populated with a couple of files (only one for the
> >+moment).
>
> s/sony_acpi\.ko/sony_acpi/
> .ko is an implementation detail the user-space should not have to care
> about.

yup.

> >+For example:
> >+ # echo "1" > /proc/acpi/sony/brt
>
> BTW, why not naming the file "brightness" instead? Most acpi files have
> "long" names like that. At least people can easily figure out what the
> files are for.

Agreed.

> >+config ACPI_SONY
> >+ tristate "Sony Laptop Extras"
> >+ depends on X86
> >+ depends on ACPI_INTERPRETER
> >+ default m
> >+ ---help---
> >+ This mini-driver drives the ACPI SNC device present in the
> >+ ACPI BIOS of the Sony Vaio laptops.
> >+
> >+ It gives access to some extra laptop functionalities. In
> >+ its current form, the only thing this driver does is letting
> >+ the user set or query the screen brightness.
> >+
> >+ Read <Documentation/sony_acpi.txt> for more information.
>
> I think I remember this should be <file:Documentation...> or something
> similar.

correct.

> Note that I have next to zero knowledge of the acpi internals so I
> couldn't comment on that part.

Hey, that's not so bad :)

An updated version will follow.

Stelian.
--
Stelian Pop <stelian@popies.net>