Messages in this thread | | | From | "Fabio M. De Francesco" <> | Subject | Re: [PATCH] staging: rtl8188eu: Remove an unused variable and some lines of code | Date | Fri, 02 Jul 2021 14:14:45 +0200 |
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On Friday, July 2, 2021 10:35:21 AM CEST Dan Carpenter wrote: > On Fri, Jul 02, 2021 at 10:48:40AM +0300, Dan Carpenter wrote: > > On Thu, Jul 01, 2021 at 04:47:07PM +0200, Fabio M. De Francesco wrote: > > > Remove set but unused iw_operation_mode[]. Remove all the lines of > > > code from the function rtw_wx_set_rate, except the "return 0;" line > > > to not break userland code that somewhat uses this IOCTL. > > > > > > Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> > > > [...] > >
Dear Dan,
> > Just delete this whole file. It doesn't do anything now. > > Sorry, I meant function, not file. *chortle*. :P
No worries, it is clear it was unintended.
Back to the function... As you may suspect :-) I know practically nothing neither of Linux device drivers or of whatever else kernel, so I take your words for good. ASAP, I'll send a v2 of this patch.
However, I usually like to understand what I make (just for fun and... more).
That rtw_wx_set_rate() is the implementation of the SIOCSIWRATE IOCTL command. I hope that I have not misunderstood it, have I?
However, we know that this function does practically nothing and then simply returns 0 to the user. That's exactly the reason why I deleted all its lines (except one).
If I am a user of that command I get a "success" return code (0) and I don't notice that it won't be able to set the bit rate. However everything should still keep running (I suppose using the default bit rate of the hardware; who really knows?).
Now it's time for two questions:
1) what happens if that command is used by some users that (hopelessly) expect the function to set the bit rate? I mean: if the function is not anymore in the list of the IOCTL commands of the rtw_handlers array will still the user program compile, link, and don't crash at runtime?
2) how should I delete the association of SIOCSIWRATE with rtw_wx_set_rate() in the rtw_handlers array? - delete the entry and shift the array one position up? - set the SIOCSIWRATE entry to NULL?
Regards,
Fabio > > regards, > dan carpenter
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