Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751965AbdF3FtV (ORCPT ); Fri, 30 Jun 2017 01:49:21 -0400 Received: from smtp.nue.novell.com ([195.135.221.5]:56613 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751577AbdF3FtU (ORCPT ); Fri, 30 Jun 2017 01:49:20 -0400 Date: Fri, 30 Jun 2017 13:49:07 +0800 From: joeyli To: "Rafael J. Wysocki" Cc: "Lee, Chun-Yi" , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Len Brown , Andy Shevchenko , Michal Hocko Subject: Re: [RFC PATCH v3] acpi: indicate to platform when hot remove returns busy Message-ID: <20170630054907.GB13714@linux-l9pv.suse> References: <20170621074544.18436-1-jlee@suse.com> <136250372.B1LmTaN194@aspire.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <136250372.B1LmTaN194@aspire.rjw.lan> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5210 Lines: 146 Hi Rafael, On Thu, Jun 29, 2017 at 12:13:18AM +0200, Rafael J. Wysocki wrote: > On Wednesday, June 21, 2017 03:45:44 PM Lee, Chun-Yi wrote: > > In hotplug logic, it always indicates non-specific failure to > > platform through _OST when handing acpi hot-remove event failed. Then > > platform terminates the hot-remove process but it can not identify > > the reason. > > > > Base on current hot-remove code, there have two situations that it > > returns busy: > > - OSPM try to offline an individual device, but the device offline > > function returns busy. > > - When the ejection event is applied to an "not offlined yet" container. > > OSPM send kobject change event to userspace and returns busy. > > > > Both of them will returns -EBUSY to acpi device hotplug function then > > hotplug function indicates non-specific failure to platform just like > > any other error, e.g. -ENODEV or -EIO. > > > > The benefit to platform for identifying the OS busy state is that > > platform can be applied different approach to handle the busy but > > not just terminate the hot-remove process by unknown reason. For > > example, platform can wait for a while then triggers hot-remove > > again. > > > > This RFC patch adds one more parameter to the handler function of > > acpi generic hotplug event to give the function a chance to propose > > the return code of _OST. In this case, it sets ost return code to > > ACPI_OST_SC_DEVICE_BUSY when the acpi hot remove function returns > > -EBUSY. > > > > v3: > > Removed redundant 'else' in acpi_ost_status_code(). (Andy Shevchenko) > > > > v2: > > Do not overwrite ost code in acpi_generic_hotplug_event(). Move > > the "error code to ost code" logic to a help function. (Andy Shevchenko) > > > > Cc: "Rafael J. Wysocki" > > Cc: Len Brown > > Cc: Andy Shevchenko > > Cc: Michal Hocko > > Signed-off-by: "Lee, Chun-Yi" > > --- > > drivers/acpi/scan.c | 21 +++++++++++++++------ > > 1 file changed, 15 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > > index 3a10d7573477..41f5065190c7 100644 > > --- a/drivers/acpi/scan.c > > +++ b/drivers/acpi/scan.c > > @@ -384,6 +384,20 @@ static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type) > > return -EINVAL; > > } > > > > +static int acpi_ost_status_code(u32 src, int error) > > +{ > > + switch (src) { > > + case ACPI_NOTIFY_EJECT_REQUEST: > > + case ACPI_OST_EC_OSPM_EJECT: > > + if (error == -EPERM) > > + return ACPI_OST_SC_EJECT_NOT_SUPPORTED; > > + if (error == -EBUSY) > > + return ACPI_OST_SC_DEVICE_BUSY; > > + break; > > + } > > + return error ? ACPI_OST_SC_NON_SPECIFIC_FAILURE : ACPI_OST_SC_SUCCESS; > > +} > > I'm not sure why you need the function above? > > It only has one user anyway. > Because different hotplug source event may has different OST code definition. So I want to use a function to handle the the complexity. The originial function like this: static int acpi_ost_status_code(u32 src, int error) { switch (src) { case ACPI_NOTIFY_EJECT_REQUEST: case ACPI_OST_EC_OSPM_EJECT: if (error == -EPERM) return ACPI_OST_SC_EJECT_NOT_SUPPORTED; if (error == -EBUSY) return ACPI_OST_SC_DEVICE_BUSY; break; case ACPI_OST_EC_OSPM_INSERTION: if (error == -EPERM) return ACPI_OST_SC_INSERT_NOT_SUPPORTED; if (error == -EBUSY) return ACPI_OST_SC_INSERT_IN_PROGRESS; break; } return error ? ACPI_OST_SC_NON_SPECIFIC_FAILURE : ACPI_OST_SC_SUCCESS; } The ACPI_OST_EC_OSPM_INSERTION represents "Insertion Processing (Source Event: 0x200)" that it has different ost code definition. Because the machine supports "Insertion" that has not yet appeared. So I removed the ACPI_OST_EC_OSPM_INSERTION case block. > > + > > void acpi_device_hotplug(struct acpi_device *adev, u32 src) > > { > > u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; > > @@ -404,10 +418,6 @@ void acpi_device_hotplug(struct acpi_device *adev, u32 src) > > error = dock_notify(adev, src); > > } else if (adev->flags.hotplug_notify) { > > error = acpi_generic_hotplug_event(adev, src); > > - if (error == -EPERM) { > > - ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED; > > - goto err_out; > > - } > > } else { > > int (*notify)(struct acpi_device *, u32); > > > > @@ -423,9 +433,8 @@ void acpi_device_hotplug(struct acpi_device *adev, u32 src) > > else > > goto out; > > } > > - if (!error) > > - ost_code = ACPI_OST_SC_SUCCESS; > > I just would do: > > switch (error) { > case 0: > ost_code = ACPI_OST_SC_SUCCESS; > break; > case -EBUSY: > ost_code = ACPI_OST_SC_DEVICE_BUSY; > break; > default: > ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; > break; > } > Currently the above switch-case works. But if considering ACPI_OST_EC_OSPM_INSERTION in the future then it's not enough. Thanks a lot! Joey Lee