[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <877cuyon5e.fsf@oltmanns.dev>
Date: Thu, 30 Mar 2023 06:45:22 +0200
From: Frank Oltmanns <frank@...manns.dev>
To: Roman Beranek <romanberanek@...oud.com>
Cc: Maxime Ripard <maxime@...no.tech>, Chen-Yu Tsai <wens@...e.org>,
David Airlie <airlied@...il.com>,
Daniel Vetter <daniel@...ll.ch>,
Jernej Skrabec <jernej.skrabec@...il.com>,
Samuel Holland <samuel@...lland.org>,
dri-devel@...ts.freedesktop.org,
linux-arm-kernel@...ts.infradead.org, linux-sunxi@...ts.linux.dev,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] drm/sun4i: uncouple DSI dotclock divider from
TCON0_DCLK_REG
Hi Roman,
On 2023-03-29 at 21:58:02 +0200, Maxime Ripard <maxime@...no.tech> wrote:
> On Tue, Mar 28, 2023 at 01:48:33AM +0200, Roman Beranek wrote:
>> On Mon Mar 27, 2023 at 10:20 PM CEST, Maxime Ripard wrote:
>> >
>> > On Sat, Mar 25, 2023 at 12:40:04PM +0100, Frank Oltmanns wrote:
>> > > Claiming to set the divider to a different value (bpp / lanes) than what we’re actually using in
>> > > the end (SUN6I_DSIO_TCON_DIV) is somehow bugging me. I feel like the proposal that I submitted is
>> > > more direct: <https://lore.kernel.org/all/20230319160704.9858-2-frank@oltmanns.dev/>
>> >
>> > Yeah, this patch looks better to me too: it's simpler, more straightforward. If Roman can confirm it
>> > works with his testing, I'll be happy to merge it.
>> >
>>
>> So I've just found out that my understanding of what sun4i_dotclock is
>> was wrong the whole time. I treated it as a virtual clock representing
>> the true CRTC pixel clock and only coincidentally also matching what
>> A64 Reference Manual labels as TCON0 data clock (a coincidence to which
>> DSI is an exception).
>>
>> Now that I finally see dotclock as 'what could dclk be an abbreviation
>> to', I to agree that it's not only straightforward but also correct to
>> keep the divider at 4 and adjust the rate as is done it the patch Frank
>> submitted.
>>
>> In order to preserve semantic correctness however, I propose to preface
>> the change with a patch that renames sun4i_dotclock and tcon-pixel-clock
>> such that dot/pixel is replaced with d/data. What do you think?
>
> I don't think it's exposed to the userspace in any way so it makes sense to me
Roman, will you please submit a V2 of the patch I submitted then? Or do
you want me to do it?
Thanks,
Frank
>
> Maxime
>
--
Powered by blists - more mailing lists