Date: Wed, 5 Jan 2022 17:06:35 -0700 From: Warner Losh <imp@bsdimp.com> To: Gleb Smirnoff <glebius@freebsd.org> Cc: Alexander Motin <mav@freebsd.org>, src-committers <src-committers@freebsd.org>, "<dev-commits-src-all@freebsd.org>" <dev-commits-src-all@freebsd.org>, dev-commits-src-main@freebsd.org Subject: Re: git: ce881170088c - main - atkbd: Disable periodic polling by default. Message-ID: <CANCZdfpAprju3odJfVQyT2J5VnvaW%2B6-LbnqJjOX9JBCAwz8MA@mail.gmail.com> In-Reply-To: <YdYyDOvHoBRklkoE@FreeBSD.org> References: <202201052013.205KD3HJ024209@gitrepo.freebsd.org> <YdYf67Wp5ofztN0r@FreeBSD.org> <CANCZdfo0asGzvD=o_4WDih9FDCeOO7sz9SgqjhOb13RSDj%2B4mQ@mail.gmail.com> <YdYyDOvHoBRklkoE@FreeBSD.org>
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--00000000000063a83005d4dea5f9 Content-Type: text/plain; charset="UTF-8" On Wed, Jan 5, 2022 at 5:04 PM Gleb Smirnoff <glebius@freebsd.org> wrote: > On Wed, Jan 05, 2022 at 04:18:25PM -0700, Warner Losh wrote: > W> On Wed, Jan 5, 2022, 3:47 PM Gleb Smirnoff <glebius@freebsd.org> wrote: > W> > W> > On Wed, Jan 05, 2022 at 08:13:03PM +0000, Alexander Motin wrote: > W> > A> commit ce881170088c4c98c036fe561f8ee8413c2e2585 > W> > A> Author: Alexander Motin <mav@FreeBSD.org> > W> > A> AuthorDate: 2022-01-05 20:00:36 +0000 > W> > A> Commit: Alexander Motin <mav@FreeBSD.org> > W> > A> CommitDate: 2022-01-05 20:12:58 +0000 > W> > A> > W> > A> atkbd: Disable periodic polling by default. > W> > A> > W> > A> It is one of the few remaining Giant-locked callouts. It > would be > W> > A> good to remove it, not mentioning that polling itself is not > good. > W> > A> > W> > A> If this cause keyboard/mouse freezes on some hardware, please > set > W> > A> loader tunable hw.atkbd.hz=1 as workaround and report the > issue. > W> > A> > W> > A> Submitted by: imp, jhb > W> > > W> > Lame question: this is related only to a keyboard plugged into PS/2, > isn't > W> > W> Yes. I think this part of the code is only for "legacy" keyboards. I > don't > W> think mice are affected, but since both attach to the keyboard > controller > W> there is a tiny chance mice might be affected in some weird hardware... > > I'd even say to legacy mainboards. Cause I have PS/2 keybooard plugged into > USB port and AFAIU it is not affected by this change in any way. > correct. Going through USB is unaffected. > I think that even if this change creates some regression, we never know > that. > Nobody would today run so old mainboard as a desktop. Might have it as a > headless appliance. > You'd be surprised what people run today :(. Doing the graphics stuff has shown me that. Nobody would build a new one today, but there's lots of systems that have been around a few years that have keyboards connected via PS/2. I doubt, though, any will see a regression because of the extreme age of this workaround. Warner --00000000000063a83005d4dea5f9 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr"><div dir=3D"ltr"><br></div><br><div class=3D"gmail_quote">= <div dir=3D"ltr" class=3D"gmail_attr">On Wed, Jan 5, 2022 at 5:04 PM Gleb S= mirnoff <<a href=3D"mailto:glebius@freebsd.org">glebius@freebsd.org</a>&= gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0= px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On We= d, Jan 05, 2022 at 04:18:25PM -0700, Warner Losh wrote:<br> W> On Wed, Jan 5, 2022, 3:47 PM Gleb Smirnoff <<a href=3D"mailto:gleb= ius@freebsd.org" target=3D"_blank">glebius@freebsd.org</a>> wrote:<br> W> <br> W> > On Wed, Jan 05, 2022 at 08:13:03PM +0000, Alexander Motin wrote:= <br> W> > A> commit ce881170088c4c98c036fe561f8ee8413c2e2585<br> W> > A> Author:=C2=A0 =C2=A0 =C2=A0Alexander Motin <mav@FreeBSD= .org><br> W> > A> AuthorDate: 2022-01-05 20:00:36 +0000<br> W> > A> Commit:=C2=A0 =C2=A0 =C2=A0Alexander Motin <mav@FreeBSD= .org><br> W> > A> CommitDate: 2022-01-05 20:12:58 +0000<br> W> > A><br> W> > A>=C2=A0 =C2=A0 =C2=A0atkbd: Disable periodic polling by defa= ult.<br> W> > A><br> W> > A>=C2=A0 =C2=A0 =C2=A0It is one of the few remaining Giant-lo= cked callouts.=C2=A0 It would be<br> W> > A>=C2=A0 =C2=A0 =C2=A0good to remove it, not mentioning that = polling itself is not good.<br> W> > A><br> W> > A>=C2=A0 =C2=A0 =C2=A0If this cause keyboard/mouse freezes on= some hardware, please set<br> W> > A>=C2=A0 =C2=A0 =C2=A0loader tunable hw.atkbd.hz=3D1 as worka= round and report the issue.<br> W> > A><br> W> > A>=C2=A0 =C2=A0 =C2=A0Submitted by:=C2=A0 =C2=A0imp, jhb<br> W> ><br> W> > Lame question: this is related only to a keyboard plugged into P= S/2, isn't<br> W> <br> W> Yes. I think this part of the code is only for "legacy" key= boards. I don't<br> W> think mice are affected, but since both attach to the keyboard contro= ller<br> W> there is a tiny chance mice might be affected in some weird hardware.= ..<br> <br> I'd even say to legacy mainboards. Cause I have PS/2 keybooard plugged = into<br> USB port and AFAIU it is not affected by this change in any way.<br></block= quote><div><br></div><div>correct. Going through USB is unaffected.</div><d= iv>=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0p= x 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> I think that even if this change creates some regression, we never know tha= t.<br> Nobody would today run so old mainboard as a desktop. Might have it as a<br= > headless appliance.<br></blockquote><div><br></div><div>You'd be surpri= sed what people run today :(. Doing the graphics stuff has shown</div><div>= me that. Nobody would build a new one today, but there's lots of system= s that have</div><div>been around a few years that have keyboards connected= via PS/2. I doubt, though,</div><div>any will see a regression because of = the extreme age of this workaround.</div><div><br></div><div>Warner</div></= div></div> --00000000000063a83005d4dea5f9--
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