[PATCH] Setting quality in scan results

Jouni Malinen jkmaline
Wed Apr 28 21:29:58 PDT 2004

On Wed, Apr 21, 2004 at 12:57:46PM -0400, Pavel Roskin wrote:

> Scan results show random "quality" because it's never set.  The firmware
> only provides quality as part of HFA384X_RID_COMMSQUALITY request.  For
> scan results, only signal and noise are provided.  I think "quality" is
> not really applicable for a single probe response.

Random?? It is cleared to zero in __prism2_translate_scan() (memset).

> However, iwlist requires "quality" is scan results, so we should calculate
> it somehow.  I suggest to subtract noise from signal.  Since both are in
> decibels, the result should have a monotone dependency on the signal to
> noise ratio.

Is this field documented somewhere? Why is it required? I don't see much
point in reporting signal-noise separately when both of the values are
available anyway..

> iwe.u.qual.updated is not used for scan results, but it's better not to
> return a random number from the kernel to the userspace.

iwe structure is already memset to zero..

Jouni Malinen                                            PGP id EFC895FA

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