linux-kernel - Re: [PATCH v4] drm/ssd130x: Store the HW buffer in the driver-private CRTC state

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]

Message-ID: <8734zg677r.fsf@minerva.mail-host-address-is-not-set>
Date:   Thu, 14 Sep 2023 18:38:16 +0200
From:   Javier Martinez Canillas <javierm@...hat.com>
To:     Maxime Ripard <mripard@...nel.org>
Cc:     linux-kernel@...r.kernel.org,
        Thomas Zimmermann <tzimmermann@...e.de>,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        Daniel Vetter <daniel@...ll.ch>,
        David Airlie <airlied@...il.com>,
        dri-devel@...ts.freedesktop.org
Subject: Re: [PATCH v4] drm/ssd130x: Store the HW buffer in the
 driver-private CRTC state

Maxime Ripard <mripard@...nel.org> writes:

> On Thu, Sep 14, 2023 at 03:23:53PM +0200, Javier Martinez Canillas wrote:
>> Maxime Ripard <mripard@...nel.org> writes:
>> 
>> Hello Maxime,
>> 
>> > Hi,
>> >
>> > On Wed, Sep 13, 2023 at 07:29:25AM +0200, Javier Martinez Canillas wrote:
>> >>  static const struct drm_crtc_helper_funcs ssd130x_crtc_helper_funcs = {
>> >>  	.mode_valid = ssd130x_crtc_helper_mode_valid,
>> >> -	.atomic_check = drm_crtc_helper_atomic_check,
>> >> +	.atomic_check = ssd130x_crtc_helper_atomic_check,
>> >>  };
>> >
>> > Sorry I didn't catch that sooner, but there's no reason to call that
>> > function a helper.
>> >
>> 
>> Yeah, agreed that there's no reason but others drivers already add the
>> _helper prefix for struct drm_*_helper_funcs callbacks, and I did that
>> in this driver as well to follow (what appears to be?) a convention.
>
> From a quick grep, it looks like it's the exception rather than the norm
>

Ah, I guess that was just unlucky when looking at others drivers as
reference when writing this one.

>> So I've to that now for the struct drm_crtc_helper_funcs handlers to be
>> consistent with the rest of the driver, e.g for plane:
>> 
>> static const struct drm_plane_helper_funcs ssd130x_primary_plane_helper_funcs = {
>> 	DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
>> 	.atomic_check = ssd130x_primary_plane_helper_atomic_check,
>> 	.atomic_update = ssd130x_primary_plane_helper_atomic_update,
>> 	.atomic_disable = ssd130x_primary_plane_helper_atomic_disable,
>> };
>> 
>> static const struct drm_plane_funcs ssd130x_primary_plane_funcs = {
>> 	.update_plane = drm_atomic_helper_update_plane,
>> 	.disable_plane = drm_atomic_helper_disable_plane,
>> 	.reset = ssd130x_primary_plane_reset,
>> 	.atomic_duplicate_state = ssd130x_primary_plane_duplicate_state,
>> 	.atomic_destroy_state = ssd130x_primary_plane_destroy_state,
>> 	.destroy = drm_plane_cleanup,
>> };
>
> Ack.
>
> I still believe we should be removing the helper part, those are not
> helpers. But it's not a big deal anyway.
>

Probably it comes down to semantics since one could argue that are helper
functions in the driver that are used as callbacks.

But yes, I agree that if is not the norm, it's better to get rid of those.
I'll post a follow-up patch.

> Maxime

-- 
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat