From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mika Westerberg Subject: Re: [PATCH V2] ACPI: Add _DEP(Operation Region Dependencies) support to fix battery issue on the Asus T100TA Date: Thu, 20 Nov 2014 16:27:30 +0200 Message-ID: <20141120142730.GP1309@lahna.fi.intel.com> References: <1416492733-18597-1-git-send-email-tianyu.lan@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1416492733-18597-1-git-send-email-tianyu.lan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Lan Tianyu Cc: rjw-LthD3rsA81gm4RdzfppkhA@public.gmane.org, lenb-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org, robert.moore-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, lv.zheng-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, shigorin-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, adamw-cfjF3rc+CpsYNetmKr+vY16hYfS7NtTn@public.gmane.org, jan.brummer-sgYkR6nYkOfYtjvyW6yDsg@public.gmane.org, linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devel-E0kO6a4B6psdnm+yROfE0A@public.gmane.org List-Id: linux-i2c@vger.kernel.org On Thu, Nov 20, 2014 at 10:12:12PM +0800, Lan Tianyu wrote: > ACPI 5.0 introduces _DEP to designate device objects that OSPM should > assign a higher priority in start ordering due to future operation region > accesses. > > On Asus T100TA, ACPI battery info are read from a I2C slave device via > I2C operation region. Before I2C operation region handler is installed, > battery _STA always returns 0. There is a _DEP method of designating > start order under battery device node. > > This patch is to implement _DEP feature to fix battery issue on the Asus T100TA. > Introducing acpi_dep_list and adding dep_unmet count in the struct > acpi_device. During ACPI namespace scan, create struct acpi_dep_data for a > valid pair of master (device pointed to by _DEP)/slave(device with _DEP), record > master's and slave's ACPI handle in it and put it into acpi_dep_list. The dep_unmet > count will increase by one if there is a device under its _DEP. Driver's probe() should > return EPROBE_DEFER when find dep_unmet is larger than 0. When I2C operation > region handler is installed, remove all struct acpi_dep_data on the acpi_dep_list > whose master is pointed to I2C host controller and decrease slave's dep_unmet. > When dep_unmet decreases to 0, all _DEP conditions are met and then do acpi_bus_attach() > for the device in order to resolve battery _STA issue on the Asus T100TA. > > Reference: https://bugzilla.kernel.org/show_bug.cgi?id=69011 > Tested-by: Jan-Michael Brummer > Tested-by: Adam Williamson > Tested-by: Michael Shigorin > Acked-by: Wolfram Sang > Signed-off-by: Lan Tianyu Looks good to me now, Acked-by: Mika Westerberg