linux-kernel - Re: [PATCH] Revert "ACPI / video: Add HP EliteBook Revolve 810 to the blacklist"

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Message-ID: <s5hfvnl23pq.wl%tiwai@suse.de>
Date:	Fri, 14 Feb 2014 15:01:21 +0100
From:	Takashi Iwai <tiwai@...e.de>
To:	Mika Westerberg <mika.westerberg@...ux.intel.com>
Cc:	linux-acpi@...r.kernel.org,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Len Brown <lenb@...nel.org>, Aaron Lu <aaron.lu@...el.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Revert "ACPI / video: Add HP EliteBook Revolve 810 to the blacklist"

At Fri, 14 Feb 2014 16:03:16 +0200,
Mika Westerberg wrote:
> 
> On Fri, Feb 14, 2014 at 02:37:00PM +0100, Takashi Iwai wrote:
> > At Fri, 14 Feb 2014 14:34:07 +0200,
> > Mika Westerberg wrote:
> > > 
> > > This reverts commit e18ac62fa4b3f16234bab0d5a6627c57dbae9e7e.
> > > 
> > > The referenced commit added HP EliteBook Revolve 810 to the ACPI video
> > > detected blacklist so that only the native Intel backlight interface was
> > > exported.
> > > 
> > > However, this turned to be wrong solution after all. The ACPI video
> > > interface works and as long as we only use that there are no problems. So
> > > we can revert this commit and stick to use the backlight interface provided
> > > by the ACPI video driver.
> > > 
> > > (Using Intel native interface will not work after resume since the ACPI
> > > video driver will restore it's state which takes control over the native
> > > one. That's a separate thing and should be addressed in the ACPI video
> > > driver, I suppose.)
> > > 
> > > References: https://bugzilla.kernel.org/show_bug.cgi?id=70231
> > > Cc: Aaron Lu <aaron.lu@...el.com>
> > > Signed-off-by: Mika Westerberg <mika.westerberg@...ux.intel.com>
> > > ---
> > > Rafael, 
> > > 
> > > This turned out to be misunderstanding from my side. I should have
> > > investigated this further before submitting the original patch. Sorry about
> > > that.
> > > 
> > > Aaron,
> > > 
> > > Thanks for the investigation and pointing me to the right direction (e.g to
> > > use acpi_video0 over the native one).
> > 
> > Could you check whether the ACPI video still really works even if you
> > remove the recent acpi_osi blacklist entry below?  It might be that
> > BIOS changed its mind to behave more kindly as if handling for Win7.
> > 
> > 
> > Takashi
> > 
> > ---
> > diff --git a/drivers/acpi/blacklist.c b/drivers/acpi/blacklist.c
> > index 10e4964d051a..64d14406465d 100644
> > --- a/drivers/acpi/blacklist.c
> > +++ b/drivers/acpi/blacklist.c
> > @@ -322,6 +322,7 @@ static struct dmi_system_id acpi_osi_dmi_table[] __initdata = {
> >  		     DMI_MATCH(DMI_PRODUCT_VERSION, "2349D15"),
> >  		},
> >  	},
> > +#if 0
> >  	{
> >  	.callback = dmi_disable_osi_win8,
> >  	.ident = "HP ProBook 2013 models",
> > @@ -372,6 +373,7 @@ static struct dmi_system_id acpi_osi_dmi_table[] __initdata = {
> >  		     DMI_MATCH(DMI_PRODUCT_NAME, "HP EliteBook 8780w"),
> >  		},
> >  	},
> > +#endif
> >  
> >  	/*
> >  	 * BIOS invocation of _OSI(Linux) is almost always a BIOS bug.
> 
> After this patch is applied, the ACPI backlight doesn't work anymore. The
> brightness stays the same, no matter what I do.

So, you need the video blacklist when acpi_osi blacklist doesn't
exist, right?

If the video blacklist works, it should be widened to match the
all recent HP machines as acpi_osi blacklist does (ProBook, EliteBook
and co).  These are known to behave same.  Then, after checking
hp-wireless is working, we can get rid of acpi_osi hack.


Takashi
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