mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Bui Duc Phuc <phucduc.bui@gmail.com>
To: Mark Brown <broonie@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	rafael@kernel.org,  Danilo Krummrich <dakr@kernel.org>,
	linux-kernel@vger.kernel.org, driver-core@lists.linux.dev
Subject: Re: [PATCH] regcache: disable cache_only before rewriting paging registers
Date: Mon, 13 Jul 2026 20:07:13 +0700	[thread overview]
Message-ID: <CAABR9nHfThjz99fVyoAZcSdOh09-n0_WfM2OWL4zkSZG5Pm7Dg@mail.gmail.com> (raw)
In-Reply-To: <24ce60c7-5539-4fba-8bf3-3a10875c3b75@sirena.org.uk>

Hi Mark,

Thanks for the feedback.

>
> No, any access to the hardware is buggy - the whole point of cache only
> mode is that we can't access the hardware.  The paging register is part
> of the context that needs to be rewritten when resyncing the cache.

To provide some context: I based this patch on your previous commit here:

https://patchew.org/linux/20231026-regmap-fix-selector-sync-v1-1-633ded82770d@kernel.org/

Reading that commit, I mistakenly understood that we must enforce
the hardware writes here at all costs. However, based on your explanation,
I see that I misunderstood the architectural intent.

Just to clarify for my understanding: does this mean regcache_sync()
is strictly
expected to be called only after cache_only has been set to false?

If so, I will drop this patch.

Best regards,
Phuc

  reply	other threads:[~2026-07-13 13:07 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-13  7:30 phucduc.bui
2026-07-13 11:58 ` Mark Brown
2026-07-13 13:07   ` Bui Duc Phuc [this message]
2026-07-13 13:43     ` Mark Brown
2026-07-13 14:59       ` Bui Duc Phuc
2026-07-13 15:06         ` Mark Brown
2026-07-13 21:58           ` Bui Duc Phuc
2026-07-14 11:23             ` Mark Brown
2026-07-14 23:02               ` Bui Duc Phuc

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=CAABR9nHfThjz99fVyoAZcSdOh09-n0_WfM2OWL4zkSZG5Pm7Dg@mail.gmail.com \
    --to=phucduc.bui@gmail.com \
    --cc=broonie@kernel.org \
    --cc=dakr@kernel.org \
    --cc=driver-core@lists.linux.dev \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rafael@kernel.org \
    /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