From: Darren Hart <dvhart@infradead.org> To: Gabriele Mazzotta <gabriele.mzt@gmail.com>, Rafael Wysocki <rjw@rjwysocki.net> Cc: "Pali Rohár" <pali.rohar@gmail.com>, "D. Jared Dominguez" <Jared_Dominguez@dell.com>, "platform-driver-x86@vger.kernel.org" <platform-driver-x86@vger.kernel.org>, "Rafael J. Wysocki" <rjw@rjwysocki.net>, "Alex Hung" <alex.hung@canonical.com>, "Andrei Borzenkov" <arvidjaar@gmail.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org> Subject: Re: [PATCH v3] dell-rbtn: Ignore ACPI notifications if device is suspended Date: Mon, 28 Mar 2016 10:33:09 -0700 [thread overview] Message-ID: <20160328173309.GA26086@dvhart-mobl5.amr.corp.intel.com> (raw) In-Reply-To: <CABFtUbTy+zWgGOk4C998yNn=A91VF5o7ye5piTN5CuSBFKW9_g@mail.gmail.com> On Thu, Mar 24, 2016 at 12:24:56PM +0100, Gabriele Mazzotta wrote: > 2016-03-24 10:39 GMT+01:00 Pali Rohár <pali.rohar@gmail.com>: > > On Monday 21 March 2016 16:13:34 Gabriele Mazzotta wrote: > >> 2016-03-21 13:17 GMT+01:00 Pali Rohár <pali.rohar@gmail.com>: > >> > On Friday 18 March 2016 23:44:23 Gabriele Mazzotta wrote: > >> >> +#ifdef CONFIG_PM_SLEEP > >> >> +static void ACPI_SYSTEM_XFACE rbtn_acpi_clear_flag(void *context) > >> >> +{ > >> >> + struct rbtn_data *rbtn_data = context; > >> >> + > >> >> + rbtn_data->suspended = false; > >> >> +} > >> >> + > >> >> +static int rbtn_suspend(struct device *dev) > >> >> +{ > >> >> + struct acpi_device *device = to_acpi_device(dev); > >> >> + struct rbtn_data *rbtn_data = acpi_driver_data(device); > >> >> + > >> >> + rbtn_data->suspended = true; > >> >> + > >> >> + return 0; > >> >> +} > >> >> + > >> >> +static int rbtn_resume(struct device *dev) > >> >> +{ > >> >> + struct acpi_device *device = to_acpi_device(dev); > >> >> + struct rbtn_data *rbtn_data = acpi_driver_data(device); > >> >> + acpi_status status; > >> >> + > >> >> + /* > >> >> + * Clear the flag only after we received the extra > >> >> + * ACPI notification. > >> >> + */ > >> >> + status = acpi_os_execute(OSL_NOTIFY_HANDLER, > >> >> + rbtn_acpi_clear_flag, rbtn_data); > >> >> + if (ACPI_FAILURE(status)) > >> >> + rbtn_data->suspended = false; > >> > > >> > I case when acpi_os_execute success it calls rbtn_acpi_clear_flag, > >> > right? And that will set suspended to false. When acpi_os_execute fails, > >> > then it set suspended too to false... Then whole acpi_os_execute doing > >> > just "barrier" after which suspended flag can be set to false. So I > >> > think rbtn_acpi_clear_flag function is not needed here. > >> > > >> > Cannot you pass NULL or empty function pointer as callback? Or what was > >> > reason to do that flag clearing at "two places"? > >> > >> acpi_os_execute doesn't wait for the callback to be executed, so > >> I can't clear the flag from rbtn_resume. > > > > acpi_os_execute calls callback asynchronously later? Or what exactly do it? > > In this case, it adds the callback to the kacpi_notify_wq workqueue > for deferred execution. +Rafael for context/advice on the use of acpi_os_execute here. This is true, but a quick scan through that call path doesn't tell me why we would need to call it here instead of just setting rbtn_data->suspended = false. The comment suggests waiting for the event, but is that what this is doing? It appears to me to be immediately scheduling the function to a work queue, not waiting for the event notifier. Also, since there is no indication to the user that a failure occurs, this function is basically equivalent in the success and failure case (the success case is just slower). Am I missing something critical here? > > > -- > > Pali Rohár > > pali.rohar@gmail.com > -- Darren Hart Intel Open Source Technology Center
WARNING: multiple messages have this Message-ID (diff)
From: Darren Hart <dvhart@infradead.org> To: Gabriele Mazzotta <gabriele.mzt@gmail.com> Cc: "Pali Rohár" <pali.rohar@gmail.com>, "D. Jared Dominguez" <Jared_Dominguez@dell.com>, "platform-driver-x86@vger.kernel.org" <platform-driver-x86@vger.kernel.org>, "Rafael J. Wysocki" <rjw@rjwysocki.net>, "Alex Hung" <alex.hung@canonical.com>, "Andrei Borzenkov" <arvidjaar@gmail.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org> Subject: Re: [PATCH v3] dell-rbtn: Ignore ACPI notifications if device is suspended Date: Mon, 28 Mar 2016 10:33:09 -0700 [thread overview] Message-ID: <20160328173309.GA26086@dvhart-mobl5.amr.corp.intel.com> (raw) In-Reply-To: <CABFtUbTy+zWgGOk4C998yNn=A91VF5o7ye5piTN5CuSBFKW9_g@mail.gmail.com> On Thu, Mar 24, 2016 at 12:24:56PM +0100, Gabriele Mazzotta wrote: > 2016-03-24 10:39 GMT+01:00 Pali Rohár <pali.rohar@gmail.com>: > > On Monday 21 March 2016 16:13:34 Gabriele Mazzotta wrote: > >> 2016-03-21 13:17 GMT+01:00 Pali Rohár <pali.rohar@gmail.com>: > >> > On Friday 18 March 2016 23:44:23 Gabriele Mazzotta wrote: > >> >> +#ifdef CONFIG_PM_SLEEP > >> >> +static void ACPI_SYSTEM_XFACE rbtn_acpi_clear_flag(void *context) > >> >> +{ > >> >> + struct rbtn_data *rbtn_data = context; > >> >> + > >> >> + rbtn_data->suspended = false; > >> >> +} > >> >> + > >> >> +static int rbtn_suspend(struct device *dev) > >> >> +{ > >> >> + struct acpi_device *device = to_acpi_device(dev); > >> >> + struct rbtn_data *rbtn_data = acpi_driver_data(device); > >> >> + > >> >> + rbtn_data->suspended = true; > >> >> + > >> >> + return 0; > >> >> +} > >> >> + > >> >> +static int rbtn_resume(struct device *dev) > >> >> +{ > >> >> + struct acpi_device *device = to_acpi_device(dev); > >> >> + struct rbtn_data *rbtn_data = acpi_driver_data(device); > >> >> + acpi_status status; > >> >> + > >> >> + /* > >> >> + * Clear the flag only after we received the extra > >> >> + * ACPI notification. > >> >> + */ > >> >> + status = acpi_os_execute(OSL_NOTIFY_HANDLER, > >> >> + rbtn_acpi_clear_flag, rbtn_data); > >> >> + if (ACPI_FAILURE(status)) > >> >> + rbtn_data->suspended = false; > >> > > >> > I case when acpi_os_execute success it calls rbtn_acpi_clear_flag, > >> > right? And that will set suspended to false. When acpi_os_execute fails, > >> > then it set suspended too to false... Then whole acpi_os_execute doing > >> > just "barrier" after which suspended flag can be set to false. So I > >> > think rbtn_acpi_clear_flag function is not needed here. > >> > > >> > Cannot you pass NULL or empty function pointer as callback? Or what was > >> > reason to do that flag clearing at "two places"? > >> > >> acpi_os_execute doesn't wait for the callback to be executed, so > >> I can't clear the flag from rbtn_resume. > > > > acpi_os_execute calls callback asynchronously later? Or what exactly do it? > > In this case, it adds the callback to the kacpi_notify_wq workqueue > for deferred execution. +Rafael for context/advice on the use of acpi_os_execute here. This is true, but a quick scan through that call path doesn't tell me why we would need to call it here instead of just setting rbtn_data->suspended = false. The comment suggests waiting for the event, but is that what this is doing? It appears to me to be immediately scheduling the function to a work queue, not waiting for the event notifier. Also, since there is no indication to the user that a failure occurs, this function is basically equivalent in the success and failure case (the success case is just slower). Am I missing something critical here? > > > -- > > Pali Rohár > > pali.rohar@gmail.com > -- Darren Hart Intel Open Source Technology Center
next prev parent reply other threads:[~2016-03-28 17:35 UTC|newest] Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-03-11 23:49 [PATCH v2] dell-rbtn: Ignore ACPI notifications if device is suspended Gabriele Mazzotta 2016-03-14 7:55 ` Alex Hung 2016-03-14 7:55 ` Alex Hung 2016-03-14 11:34 ` Gabriele Mazzotta 2016-03-14 11:34 ` Gabriele Mazzotta 2016-03-14 11:45 ` Pali Rohár 2016-03-14 11:45 ` Pali Rohár 2016-03-14 12:15 ` Andrei Borzenkov 2016-03-14 12:15 ` Andrei Borzenkov 2016-03-18 15:57 ` Andrei Borzenkov 2016-03-18 15:57 ` Andrei Borzenkov 2016-04-18 12:31 ` Pali Rohár 2016-04-18 12:31 ` Pali Rohár 2016-03-18 22:44 ` [PATCH v3] " Gabriele Mazzotta 2016-03-21 12:17 ` Pali Rohár 2016-03-21 15:13 ` Gabriele Mazzotta 2016-03-21 15:13 ` Gabriele Mazzotta 2016-03-24 9:39 ` Pali Rohár 2016-03-24 9:39 ` Pali Rohár 2016-03-24 11:24 ` Gabriele Mazzotta 2016-03-24 11:24 ` Gabriele Mazzotta 2016-03-28 17:33 ` Darren Hart [this message] 2016-03-28 17:33 ` Darren Hart 2016-03-28 17:58 ` Gabriele Mazzotta 2016-03-28 18:56 ` Darren Hart 2016-03-28 19:41 ` Gabriele Mazzotta 2016-03-29 5:24 ` Darren Hart 2016-03-29 11:13 ` Gabriele Mazzotta 2016-03-29 13:11 ` Rafael J. Wysocki 2016-04-18 12:35 ` Pali Rohár 2016-04-18 12:35 ` Pali Rohár 2016-04-25 20:06 ` Gabriele Mazzotta 2016-04-25 20:06 ` Gabriele Mazzotta 2016-05-19 13:30 ` Pali Rohár 2016-05-19 13:30 ` Pali Rohár 2016-05-19 20:18 ` Darren Hart 2016-05-19 20:18 ` Darren Hart 2016-05-23 21:26 ` Darren Hart 2016-05-23 21:26 ` Darren Hart 2016-05-23 22:06 ` Pali Rohár 2016-05-23 22:06 ` Pali Rohár 2016-05-23 22:17 ` Darren Hart 2016-05-23 22:17 ` Darren Hart 2016-05-23 22:22 ` Pali Rohár 2016-05-23 22:22 ` Pali Rohár 2016-05-23 23:03 ` Gabriele Mazzotta 2016-05-23 23:03 ` Gabriele Mazzotta 2016-05-24 3:48 ` Andrei Borzenkov 2016-05-24 3:48 ` Andrei Borzenkov 2016-05-24 7:09 ` Pali Rohár 2016-05-24 7:09 ` Pali Rohár 2016-05-24 19:57 ` Darren Hart 2016-05-24 19:57 ` Darren Hart 2016-05-24 20:53 ` [PATCH v4] " Gabriele Mazzotta 2016-05-25 20:28 ` Darren Hart 2016-05-25 20:36 ` Pali Rohár 2016-05-25 20:47 ` Gabriele Mazzotta 2016-05-25 21:20 ` Darren Hart
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=20160328173309.GA26086@dvhart-mobl5.amr.corp.intel.com \ --to=dvhart@infradead.org \ --cc=Jared_Dominguez@dell.com \ --cc=alex.hung@canonical.com \ --cc=arvidjaar@gmail.com \ --cc=gabriele.mzt@gmail.com \ --cc=linux-kernel@vger.kernel.org \ --cc=pali.rohar@gmail.com \ --cc=platform-driver-x86@vger.kernel.org \ --cc=rjw@rjwysocki.net \ /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: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.