Messages in this thread | | | From | Javier Martinez Canillas <> | Subject | Re: [PATCH] drm/ssd130x: Drop _helper prefix from struct drm_*_helper_funcs callbacks | Date | Thu, 21 Sep 2023 10:23:42 +0200 |
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Geert Uytterhoeven <geert@linux-m68k.org> writes:
Hello Geert and Maxime,
> Hi Maxime, > > On Thu, Sep 21, 2023 at 9:44 AM Maxime Ripard <mripard@kernel.org> wrote: >> On Mon, Sep 18, 2023 at 09:19:07AM +0200, Javier Martinez Canillas wrote: >> > Thomas Zimmermann <tzimmermann@suse.de> writes: >> > > Am 14.09.23 um 21:51 schrieb Javier Martinez Canillas: >> > >> The driver uses a naming convention where functions for struct drm_*_funcs >> > >> callbacks are named ssd130x_$object_$operation, while the callbacks for >> > >> struct drm_*_helper_funcs are named ssd130x_$object_helper_$operation. >> > >> >> > >> The idea is that this helper_ prefix in the function names denote that are >> > >> for struct drm_*_helper_funcs callbacks. This convention was copied from >> > >> other drivers, when ssd130x was written but Maxime pointed out that is the >> > >> exception rather than the norm. >> > > >> > > I guess you found this in my code. I want to point out that I use the >> > > _helper infix to signal that these are callback for >> > > drm_primary_plane_helper_funcs and *not* drm_primary_plane_funcs. The >> > > naming is intentional. >> > >> > Yes, that's what tried to say in the commit message and indeed I got the >> > convention from drivers in drivers/gpu/drm/tiny. In fact I believe these >> > function names are since first iteration of the driver, when was meant to >> > be a tiny driver. >> > >> > According to Maxime it's the exception rather than the rule and suggested >> > to change it, I don't really have a strong opinion on either naming TBH. >> >> Maybe that's just me, but the helper in the name indeed throws me off. In my >> mind, it's supposed to be used only for helpers, not functions implementing the >> helpers hooks.
I agree with your definition of helpers. But more importantly for me is what you mentioned, that most DRM drivers aren't using this convention of concatenating the driver name + struct type name + callback name.
> > With several callbacks using the same (field) name, it is very helpful > to name the actual implementation by combining the struct type name > and the field name. Anything else confuses the casual reader.
Both options have cons and pros (e.g: quickly figuring out to what struct callback is associated as you said), but the reason I posted this patch is to attempt making the driver more consistent with the rest of the drivers.
> Perhaps the real question is whether the structures should have "helper" > in their name in the first place? >
Indeed. I never fully understood why the DRM/KMS objects callbacks are split in drm_$object_funcs and drm_$object_helper_funcs structs. AFAIU is because the former is the minimum required and the latter is to add additional custom behavior ?
I read this section of the documentation but still isn't clear to me:
https://dri.freedesktop.org/docs/drm/gpu/drm-kms-helpers.html
> Just my 2€c as a DRM novice... >
-- Best regards,
Javier Martinez Canillas Core Platforms Red Hat
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