From: Adrian Ratiu <adrian.ratiu@collabora.com>
To: Mark Brown <broonie@kernel.org>,
Adrian Ratiu <adrian.ratiu@collabora.com>
Cc: Fruehberger Peter <Peter.Fruehberger@de.bosch.com>,
kernel@collabora.com, Philipp Zabel <p.zabel@pengutronix.de>,
linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org,
kuhanh.murugasen.krishnan@intel.com,
Daniel Vetter <daniel@ffwll.ch>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Ezequiel Garcia <ezequiel@collabora.com>,
linux-media@vger.kernel.org
Subject: Re: [PATCH 07/18] regmap: mmio: add config option to allow relaxed MMIO accesses
Date: Wed, 14 Oct 2020 16:00:38 +0300 [thread overview]
Message-ID: <87lfg97yix.fsf@collabora.com> (raw)
In-Reply-To: <20201014121249.GA4580@sirena.org.uk>
On Wed, 14 Oct 2020, Mark Brown <broonie@kernel.org> wrote:
> On Wed, Oct 14, 2020 at 02:51:14PM +0300, Adrian Ratiu wrote:
>> On Tue, 13 Oct 2020, Mark Brown <broonie@kernel.org> wrote:
>> > On Mon, Oct 12, 2020 at 11:59:46PM +0300, Adrian Ratiu wrote:
>
>> > > - writeb(val, ctx->regs + reg); + if
>> > > (ctx->relaxed_mmio) + writeb_relaxed(val, ctx->regs + reg);
>> > > + else + writeb(val, ctx->regs + reg);
>
>> > There is no point in doing a conditional operation on every
>> > I/O, it'd be better to register a different set of ops when
>> > doing relaxed I/O.
>
>> Indeed I have considered adding new functions but went with
>> this solution because it's easier for the users to only have to
>> define a "relaxed" config then test the regmap ctx as above.
>
> It seems like you've taken this in a direction other than what
> I was thinking of here - defining separate ops doesn't mean we
> have to do anything which has any impact on the interface seen
> by users. The regmap config is supplied at registration time,
> it's just as available then as it is when doing I/O.
Right. I got confused by the meaning of ops :) Sorry about that.
>
>> Thinking a bit more about it, yes, it makes more sense to have
>> dedicated ops: this way users don't have to be explicit about
>> adding membarriers and can combine relaxed and non-relaxed more
>> easily, so it's also a better API trade-off in addition to
>> avoiding the conditional. Thanks!
>
> I'm not sure what you're proposing here - it does seem useful to
> be able to combine relaxed and non-relaxed I/O but that seems
> like it'd break down the abstraction for regmap since tht's not
> really a concept other buses are going to have? Unless we
> provide an operation to switch by setting flags or somethin
> possibly and integrate it with the cache perhaps. Could you be
> a bit more specific about what you were thinking of here please?
I was thinking about exposing a relaxed API like
regmap_write_relaxed but now that I know what you meant by ops and
also that it doesn't make sense for other busses / violates the
abstraction, I realize that is a bad idea and I will continue
improving this to avoid the conditional and send a separete
patch. Thanks again!
>
>> Question: Do you want me to split this patch from the series and send it
>> separately just for the regmap subsystem to be easier to review / apply?
>
> Sure.
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
next prev parent reply other threads:[~2020-10-14 12:59 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-12 20:59 [PATCH 00/18] Add Hantro regmap and VC8000 h264 decode support Adrian Ratiu
2020-10-12 20:59 ` [PATCH 01/18] media: hantro: document all int reg bits up to vc8000 Adrian Ratiu
2020-10-12 20:59 ` [PATCH 02/18] media: hantro: make consistent use of decimal register notation Adrian Ratiu
2020-10-12 20:59 ` [PATCH 03/18] media: hantro: make G1_REG_SOFT_RESET Rockchip specific Adrian Ratiu
2020-10-12 20:59 ` [PATCH 04/18] media: hantro: add reset controller support Adrian Ratiu
2020-10-13 8:11 ` Philipp Zabel
2020-10-12 20:59 ` [PATCH 05/18] media: hantro: prepare clocks before variant inits are run Adrian Ratiu
2020-10-12 20:59 ` [PATCH 06/18] media: hantro: imx8mq: simplify ctrlblk reset logic Adrian Ratiu
2020-10-12 20:59 ` [PATCH 07/18] regmap: mmio: add config option to allow relaxed MMIO accesses Adrian Ratiu
2020-10-13 10:26 ` Mark Brown
2020-10-14 11:51 ` Adrian Ratiu
2020-10-14 12:12 ` Mark Brown
2020-10-14 13:00 ` Adrian Ratiu [this message]
2020-10-12 20:59 ` [PATCH 08/18] media: hantro: add initial MMIO regmap infrastructure Adrian Ratiu
2020-10-12 20:59 ` [PATCH 09/18] media: hantro: default regmap to relaxed MMIO Adrian Ratiu
2020-10-12 20:59 ` [PATCH 10/18] media: hantro: convert G1 h264 decoder to regmap fields Adrian Ratiu
2020-10-12 20:59 ` [PATCH 11/18] media: hantro: convert G1 postproc to regmap Adrian Ratiu
2020-10-12 20:59 ` [PATCH 12/18] media: hantro: add VC8000D h264 decoding Adrian Ratiu
2020-10-12 20:59 ` [PATCH 13/18] media: hantro: add VC8000D postproc support Adrian Ratiu
2020-10-12 20:59 ` [PATCH 14/18] media: hantro: make PP enablement logic a bit smarter Adrian Ratiu
2020-10-12 20:59 ` [PATCH 15/18] media: hantro: add user-selectable, platform-selectable H264 High10 Adrian Ratiu
2020-10-12 20:59 ` [PATCH 16/18] media: hantro: rename h264_dec as it's not G1 specific anymore Adrian Ratiu
2020-10-12 20:59 ` [PATCH 17/18] media: hantro: add dump registers debug option before decode start Adrian Ratiu
2020-10-12 20:59 ` [PATCH 18/18] media: hantro: document encoder reg fields Adrian Ratiu
2020-10-12 23:39 ` [PATCH 00/18] Add Hantro regmap and VC8000 h264 decode support Jonas Karlman
2020-10-13 6:48 ` Adrian Ratiu
2020-10-29 12:38 ` Ezequiel Garcia
2020-10-29 16:21 ` Jonas Karlman
2020-11-03 15:27 ` Ezequiel Garcia
2020-10-29 13:07 ` Ezequiel Garcia
2020-10-29 14:15 ` Robin Murphy
2020-10-29 14:48 ` Mark Brown
2020-10-29 16:27 ` Ezequiel Garcia
2020-10-29 17:59 ` Mark Brown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87lfg97yix.fsf@collabora.com \
--to=adrian.ratiu@collabora.com \
--cc=Peter.Fruehberger@de.bosch.com \
--cc=broonie@kernel.org \
--cc=daniel@ffwll.ch \
--cc=ezequiel@collabora.com \
--cc=kernel@collabora.com \
--cc=kuhanh.murugasen.krishnan@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=linux-rockchip@lists.infradead.org \
--cc=mchehab@kernel.org \
--cc=p.zabel@pengutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).