On Fri, Aug 14, 2015 at 06:18:55PM +0200, Lukas Wunner wrote: > Originally by Seth Forshee <seth.forshee@xxxxxxxxxxxxx>, 2012-10-04: > The gmux allows muxing the DDC independently from the display, so > support this functionality. This will allow reading the EDID for the > inactive GPU, fixing issues with machines that either don't have a VBT > or have invalid mode data in the VBT. > > Modified by Lukas Wunner <lukas@xxxxxxxxx>, 2015-03-27: > If the inactive client registers before the active client then > old_ddc_owner cannot be determined with find_active_client() > (null pointer dereference). Therefore change semantics of the > ->switch_ddc handler callback to return old_ddc_owner. > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861 > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115 > Tested-by: Pierre Moreau <pierre.morrow@xxxxxxx> > [MBP 5,3 2009 nvidia 9400M + 9600M GT pre-retina] > Tested-by: Paul Hordiienko <pvt.gord@xxxxxxxxx> > [MBP 6,2 2010 intel ILK + nvidia GT216 pre-retina] > Tested-by: William Brown <william@xxxxxxxxxxxxxxxx> > [MBP 8,2 2011 intel SNB + amd turks pre-retina] > Tested-by: Lukas Wunner <lukas@xxxxxxxxx> > [MBP 9,1 2012 intel IVB + nvidia GK107 pre-retina] > Tested-by: Bruno Bierbaumer <bruno@xxxxxxxxxxxxxx> > [MBP 11,3 2013 intel HSW + nvidia GK107 retina -- work in progress] > > Cc: Seth Forshee <seth.forshee@xxxxxxxxxxxxx> > Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx> > --- > drivers/platform/x86/apple-gmux.c | 25 +++++++++++++++++++++++-- > 1 file changed, 23 insertions(+), 2 deletions(-) > > diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c > index 0dec3f5..08bdf1e 100644 > --- a/drivers/platform/x86/apple-gmux.c > +++ b/drivers/platform/x86/apple-gmux.c > @@ -273,14 +273,34 @@ static const struct backlight_ops gmux_bl_ops = { > .update_status = gmux_update_status, > }; > > +static int gmux_switch_ddc(enum vga_switcheroo_client_id id) > +{ > + enum vga_switcheroo_client_id old_ddc_owner; > + > + if (gmux_read8(apple_gmux_data, GMUX_PORT_SWITCH_DDC) == 1) > + old_ddc_owner = VGA_SWITCHEROO_IGD; > + else > + old_ddc_owner = VGA_SWITCHEROO_DIS; > + > + pr_debug("Switching gmux DDC from %d to %d\n", old_ddc_owner, id); > + > + if (id == old_ddc_owner) > + return old_ddc_owner; > + > + if (id == VGA_SWITCHEROO_IGD) > + gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 1); > + else > + gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2); > + > + return old_ddc_owner; > +} > + > static int gmux_switchto(enum vga_switcheroo_client_id id) > { > if (id == VGA_SWITCHEROO_IGD) { > - gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 1); > gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2); > gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2); > } else { > - gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2); > gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3); > gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3); > } > @@ -347,6 +367,7 @@ gmux_active_client(struct apple_gmux_data *gmux_data) > } If we'd required that switchto also switches ddc then the error handling in patch 1 would be a lot simpler. switch_ddc would then only be for temporary switching while probing. -Daniel > > static struct vga_switcheroo_handler gmux_handler = { > + .switch_ddc = gmux_switch_ddc, > .switchto = gmux_switchto, > .power_state = gmux_set_power_state, > .get_client_id = gmux_get_client_id, > -- > 2.1.0 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
