Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 18 Nov 2022 14:48:32 +0800
From:   Tzung-Bi Shih <tzungbi@kernel.org>
To:     Gwendal Grignou <gwendal@chromium.org>
Cc:     dtor@chromium.org, jwerner@chromium.org, bleung@chromium.org,
        enric.balletbo@collabora.com, groeck@chromium.org,
        linux-kernel@vger.kernel.org, chrome-platform@lists.linux.dev
Subject: Re: [PATCH v3 1/1] platform/chrome: Poke kb_wake_angle attribute
 visibility when needed
Message-ID: <Y3cqwEIueri63XzH@google.com>
References: <20210804213139.4139492-1-gwendal@chromium.org>
 <20210804213139.4139492-2-gwendal@chromium.org>
 <CAPUE2usQX_uQewpCYOs3SRUo7vDDMfg=n7idNvCgThDHMqTf7w@mail.gmail.com>
 <CAPUE2uuj1qde16QWHb=0+yMW3ERhXzV7ehGcViWCfij7ADeyWg@mail.gmail.com>
 <Y3bnYT6TXGXhkh/T@google.com>
 <CAPUE2uuUn33yRMz77+XxZvK9bDzAA8u3SLBx=iDfAJc6WrUEEQ@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAPUE2uuUn33yRMz77+XxZvK9bDzAA8u3SLBx=iDfAJc6WrUEEQ@mail.gmail.com>
Precedence: bulk

On Thu, Nov 17, 2022 at 10:41:06PM -0800, Gwendal Grignou wrote:
> On Thu, Nov 17, 2022 at 6:01 PM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
> >
> > On Wed, Nov 16, 2022 at 10:23:38AM -0800, Gwendal Grignou wrote:
> > > [+chrome-platform@lists.linux.dev]
> >
> > Please also Cc to the mailing list if the patch gets chance to have
> > next version.
> >
> > > On Mon, Nov 14, 2022 at 8:10 PM Gwendal Grignou <gwendal@chromium.org> wrote:
> > [...]
> > > > > Expose the attribute group to alter to close a potiential race between
> > > > > cros-ec-sensorhub and cros-ec-sysfs (that creates the attribute group
> > > > > on behalf of the class driver).
> >
> > I failed to realize the potential race.  Could you explain it a bit?
> The decision to show or not an attribute is done at the attribute file
> creation time, once. If the module cros_ec_sysfs is loaded before
> cros_ec_sensorhub, the attribute kb_wake_angle will never be shown. If
> it is loaded after, and there are 2 accelerometers, the is_visible()
> function will return true and the attribute is shown.
> 
> This patch ensures the attribute is_visible() is run again after the
> sensorhub driver is loaded.

I see.  Thanks.