linux-kernel - Re: [PATCH 2/3] Add rfkill support to compal-laptop

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 18 Aug 2009 13:22:33 +0100
From:	Alan Jenkins <sourcejedi.lkml@...glemail.com>
To:	Mario Limonciello <mario_limonciello@...l.com>
Cc:	Marcel Holtmann <marcel@...tmann.org>, cezary.jackiewicz@...il.com,
	linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/3] Add rfkill support to compal-laptop

On 8/18/09, Alan Jenkins <sourcejedi.lkml@...glemail.com> wrote:
> On 8/18/09, Mario Limonciello <mario_limonciello@...l.com> wrote:
>> In order to be useful in modern kernels and standard interfaces,
>> compal-laptop should have rfkill support.  This patch adds it.
>> --
>> Mario Limonciello
>> *Dell | Linux Engineering*
>> mario_limonciello@...l.com
>>
>
> I have some comments of my own as well, so here goes.
>
>> +static void compal_rfkill_query(struct rfkill *rfkill, void *data)
>> +{
>> +	unsigned long radio = (unsigned long) data;
>> +	u8 result;
>> +	bool blocked;
>> +
>> +	ec_read(COMPAL_EC_COMMAND_WIRELESS, &result);
>> +
>> +	if ((result & KILLSWITCH_MASK) == 0)
>> +		blocked = 1;
>
>> +        else if (radio == WLAN_MASK)
>> +		blocked = !(result & WLAN_MASK);
>> +	else
>> +		blocked = !((result & BT_MASK) >> 1);
>
> Ick, this is overdone.  You should just be able to do
>
> +	else
> +		blocked = !(result & radio);
>
>> +	rfkill_set_sw_state(rfkill,blocked);
>> +	rfkill_set_hw_state(rfkill,0);
>
> This last line is redundant.  The HW state will default to "unblocked"
> if you never set it.
>
>> +static int compal_rfkill_set(void *data, bool blocked)
>> +{
>> +	unsigned long radio = (unsigned long) data;
>> +	u8 result, value;
>> +
>> +	ec_read(COMPAL_EC_COMMAND_WIRELESS, &result);
>> +
>> +	if ((result & KILLSWITCH_MASK) == 0)
>> +		return -EINVAL;
>> +	else {
>> +		if (!blocked)
>> +			value = (u8) (result | radio);
>> +		else
>> +			value = (u8) (result & ~radio);
>> +		ec_write(COMPAL_EC_COMMAND_WIRELESS, value);
>> +	}
>> +
>> +	return 0;
>> +}
>
> Note that the return value of rfkill_set is not propagated to
> userspace through the /dev/rfkill interface.
>
> The way you use "KILLSWITCH_MASK", it looks like a hard rfkill bit
> that covers all radios.  Why don't you report it as a hard block on
> each rfkill device?

P.S.  If you do this, you probably also want to set up polling.  I
think you should be able to reuse the query() function for the poll()
method (but you should check yourself whether that makes sense).

Thanks again
Alan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/