Re: [PATCH v2] dell-laptop: Check return value of all SMBIOS calls and do not cache hwswitch state

Darren Hart
2015-06-29T23:02:53Z

On Sat, Jun 27, 2015 at 09:34:43AM +0200, Pali Rohár wrote:
> Make sure that return value of all SMBIOS calls are properly checked and
> do not continue of processing (received) information if call failed.
>
> Also do not chache hwswitch wireless state as it can be changed at runtime
> (e.g from userspace smbios applications).

This "Also do.." tripled the size of the patch. This should really be two
patches.

>
> Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
> ---
> Changes since v1:
> * Call clear_buffer before each sequential SMBIOS call (we expect zero-filled buffer)

Another good independent patch candidate

> * Do not cache hwswitch state as it can be modified at runtime by userspace
> * simplify some conditions
> ---
> drivers/platform/x86/dell-laptop.c | 173 ++++++++++++++++++++++++++----------
> 1 file changed, 127 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
> index 35758cb..99f28d3 100644
> --- a/drivers/platform/x86/dell-laptop.c
> +++ b/drivers/platform/x86/dell-laptop.c

...

> static void dell_update_rfkill(struct work_struct *ignored)
> {
> + int hwswitch;
> int status;
> + int ret;
>
> get_buffer();
> +
> dell_send_request(buffer, 17, 11);
> + ret = buffer->output[0];
> status = buffer->output[1];
>
> + if (ret != 0)
> + goto out;
> +
> + clear_buffer();
> +
> + buffer->input[0] = 0x2;
> + dell_send_request(buffer, 17, 11);
> + ret = buffer->output[0];
> +
> + if (ret == 0 && (status & BIT(0)))
> + hwswitch = buffer->output[1];
> + else
> + hwswitch = 0;

Initializing hwswitch to 0 above saves the else and assignment line here.
Generally preferred.

...

>
> static int dell_get_intensity(struct backlight_device *bd)
> {
> - int ret = 0;
> + int ret;
> + int token;

Since we're talking respin, declare in order of descending line length please,
just as you did later when adding token to a function.

--
Darren Hart
Intel Open Source Technology Center