Messages in this thread | | | Date | Mon, 24 Apr 2023 16:20:00 +0300 (EEST) | From | Ilpo Järvinen <> | Subject | Re: [PATCH v3 1/8] tty: n_gsm: add restart parameter to DLC specific ioctl config |
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On Mon, 24 Apr 2023, Greg KH wrote:
> On Mon, Apr 24, 2023 at 11:03:26AM +0000, Starke, Daniel wrote: > > > > --- a/include/uapi/linux/gsmmux.h > > > > +++ b/include/uapi/linux/gsmmux.h > > > > @@ -58,7 +58,8 @@ struct gsm_dlci_config { > > > > __u32 priority; /* Priority (0 for default value) */ > > > > __u32 i; /* Frame type (1 = UIH, 2 = UI) */ > > > > __u32 k; /* Window size (0 for default value) */ > > > > - __u32 reserved[8]; /* For future use, must be initialized to zero */ > > > > + __u32 restart; /* Force DLCI channel reset? */ > > > > > > Why are you using a full 32 bits for just 1 bit of data here? Why not > > > use a bitfield? > > > > The ioctrl guide states: > > Bitfields and enums generally work as one would expect them to, > > but some properties of them are implementation-defined, so it is better > > to avoid them completely in ioctl interfaces. > > > > Therefore, I tried to avoid them here. > > Then use a u8?
To add further, I think that the ioctl guidance tries to say that C bitfields using :number postfix are not a good idea, not that much to disallow flag like content within an integer type.
-- i.
> > > And what happened to the request to turn the documentation for this > > > structure into proper kerneldoc format? > > > > That applied to patch 2/8 and is unrelated to this patch. Another patch > > will need to fix this. > > > > Link: https://lore.kernel.org/all/20230424075251.5216-2-daniel.starke@siemens.com/ > > It's kind of related in that the format is not right :) > > As it's a few weeks before I am allowed to even apply this, please > rework the series a bit. > > thanks, > > greg k-h >
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