> -----Original Message----- > From: Andy Shevchenko [mailto:andriy.shevchenko@xxxxxxxxxxxxxxx] > Sent: Tuesday, February 6, 2018 7:46 AM > To: Limonciello, Mario <Mario_Limonciello@xxxxxxxx>; > dmitry.torokhov@xxxxxxxxx > Cc: jdelvare@xxxxxxx; alex.hung@xxxxxxxxxxxxx; rjw@xxxxxxxxxxxxx; > lenb@xxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; davem@xxxxxxxxxxxxx; > mika.westerberg@xxxxxxxxxxxxxxx; f.fainelli@xxxxxxxxx; kishon@xxxxxx; > karniksayli1995@xxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx > Subject: Re: [PATCH 2/2] ACPI / osi: add DMI quirk for Dell systems > > On Tue, 2018-02-06 at 00:45 +0000, Mario.Limonciello@xxxxxxxx wrote: > > > > > > Playing with OSI string is a bad idea. I wouldn't do anything > > > > > while > > > > > Rafael, or even Len can confirm that is the right thing to do. > > > > > > > > > > For me, AFAIK we need to be bug-to-bug compatible with Windows > > > > > (at least > > > > > on ACPICA side), so, what Windows exactly does on such laptops? > > > > > > > > > > > > > The issue that's being worked around isn't an ACPICA interpreter > > > > issue, but it's > > > > a graphics device configuration issue. > > Then clearly nothing to do with OSI strings here, right? The usage of OSI here is: do you support the feature "Linux-Dell-Video" to Linux kernel. If Linux kernel responds yes then firmware will turn off RTD3 functionality for the discrete GPU. > > > > > Windows expects to use RTD3 on the NVIDIA GPU but Linux drivers > > > > don't. It leads to system hangs on the Linux side. > > > > > > Can we adjust Linux drivers to do the right thing? > > +100 > > > > Or is it regarding > > > the binary NVIDIA blob? > > nVidia vs. Linux again? :-) > > > > > Neither Nouveau nor the NVIDIA blob have support for RTD3. > > > > Last I heard it's waiting on NVIDIA releasing something Nouveau > > needs. So.. Eventually? For now it's better to not hang though. > > Hmm... While you are talking sense, the patch itself looks like an ugly > hack. I don't disagree it's a workaround for a driver deficiency. > > > That's part of why we wanted to enable this via a transient OSI > > string, > > to let this be removed by Linux whenever the driver does grow support. > > So, means "never" then? (Assume a bit of irony here) > > I don't know how it feels for maintainers, for me it's quite unlikely to > go (at least in this shape). I'm not going to be able to force NVIDIA to fix the blob or to give what's necessary to enable Nouvaeu for this function. What we can do is prevent someone's system from hanging because of this situation. > > I'm sorry I can't be much constructive here, I heard Len once about OSI > huge abuse by almost every party. I would rather let him speak on the > matter. I know that OSI has been abused in the past, but that's exactly why this has been implemented as seen in this patch series. It's done specifically to fit within exactly what the Linux kernel ideally looks for in a custom OSI feature string. * It has an OS Prefix (Linux-) * It's an OEM specific string (-Dell-) * It's a feature specific string (-Video) *It's specific to a single platform (not a blanket match to Dell Inc) *It only modifies one feature in ASL ��.n��������+%������w��{.n�����{�����ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
