Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-20 Thread David Woodhouse
On Tue, 2024-03-19 at 14:47 +0100, Peter Hilber wrote: > While the virtio-comment list is not available, now also CC'ing Parav, > which may be interested in this virtio-rtc spec related discussion thread. > > On 14.03.24 15:19, David Woodhouse wrote: > > On 14 March 2024 11:13:37 CET, Peter

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-19 Thread Peter Hilber
While the virtio-comment list is not available, now also CC'ing Parav, which may be interested in this virtio-rtc spec related discussion thread. On 14.03.24 15:19, David Woodhouse wrote: > On 14 March 2024 11:13:37 CET, Peter Hilber > wrote: >>> To a certain extent, as long as the virtio-rtc

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-14 Thread David Woodhouse
On 14 March 2024 11:13:37 CET, Peter Hilber wrote: >> To a certain extent, as long as the virtio-rtc device is designed to expose >> time precisely and unambiguously, it's less important if the Linux kernel >> *today* can use that. Although of course we should strive for that. Let's >>

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-14 Thread Peter Hilber
Now CC'ing the previous commenters to the virtio-rtc spec draft, since this discussion is mostly about the spec, and the Virtio mailing lists still seem to be in a migration hiatus... On 13.03.24 19:18, David Woodhouse wrote: > On 13 March 2024 17:50:48 GMT, Peter Hilber > wrote: >> On 13.03.24

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-14 Thread Peter Hilber
On 13.03.24 21:12, Andrew Lunn wrote: >> As long as it doesn't behave differently from the other RTC, I'm fine >> with this. This is important because I don't want to carry any special >> infrastructure for this driver or to have to special case this driver >> later on because it is incompatible

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-13 Thread Andrew Lunn
> As long as it doesn't behave differently from the other RTC, I'm fine > with this. This is important because I don't want to carry any special > infrastructure for this driver or to have to special case this driver > later on because it is incompatible with some evolution of the > subsystem.

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-13 Thread David Woodhouse
On 13 March 2024 17:50:48 GMT, Peter Hilber wrote: >On 13.03.24 13:45, David Woodhouse wrote: >> Surely the whole point of this effort is to provide guests with precise >> and *unambiguous* knowledge of what the time is? > >I would say, a fundamental point of this effort is to enable such

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-13 Thread Peter Hilber
On 13.03.24 15:06, David Woodhouse wrote: > On Wed, 2024-03-13 at 13:58 +0100, Alexandre Belloni wrote: >> The TSC or whatever CPU counter/clock that is used to keep the system >> time is not an RTC, I don't get why it has to be exposed as such to the >> guests. PTP is fine and precise, RTC is

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-13 Thread Peter Hilber
On 13.03.24 13:45, David Woodhouse wrote: > On Wed, 2024-03-13 at 10:45 +0100, Peter Hilber wrote: >> On 12.03.24 18:15, David Woodhouse wrote: >>> On Mon, 2024-03-11 at 19:24 +0100, Peter Hilber wrote: On 08.03.24 13:33, David Woodhouse wrote: > On Fri, 2024-03-08 at 11:32 +0100, Peter

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-13 Thread Alexandre Belloni
On 13/03/2024 14:06:42+, David Woodhouse wrote: > If you're asking why patch 7/7 in Peter's series exists to expose the > virtio clock through RTC, and you're not particularly interested in the > first six, I suppose that's a fair question. As is the question of "why > is it called virtio_rtc

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-13 Thread Peter Hilber
On 13.03.24 12:18, Alexandre Belloni wrote: > On 13/03/2024 10:45:54+0100, Peter Hilber wrote: >>> Exposing UTC as the only clock reference is bad enough; when leap >>> seconds happen there's a whole second during which you don't *know* >>> which second it is. It seems odd to me, for a precision

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-13 Thread David Woodhouse
On Wed, 2024-03-13 at 13:58 +0100, Alexandre Belloni wrote: > The TSC or whatever CPU counter/clock that is used to keep the system > time is not an RTC, I don't get why it has to be exposed as such to the > guests. PTP is fine and precise, RTC is not. Ah, I see. But the point of the virtio_rtc

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-13 Thread Alexandre Belloni
On 13/03/2024 12:29:38+, David Woodhouse wrote: > On Wed, 2024-03-13 at 12:18 +0100, Alexandre Belloni wrote: > > > > I still don't know anything about virtio but under Linux, an RTC is > > always UTC (or localtime when dual booting but let's not care) and never > > accounts for leap seconds.

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-13 Thread David Woodhouse
On Wed, 2024-03-13 at 10:45 +0100, Peter Hilber wrote: > On 12.03.24 18:15, David Woodhouse wrote: > > On Mon, 2024-03-11 at 19:24 +0100, Peter Hilber wrote: > > > On 08.03.24 13:33, David Woodhouse wrote: > > > > On Fri, 2024-03-08 at 11:32 +0100, Peter Hilber wrote: > > > > > On 07.03.24 15:02,

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-13 Thread David Woodhouse
On Wed, 2024-03-13 at 12:18 +0100, Alexandre Belloni wrote: > > I still don't know anything about virtio but under Linux, an RTC is > always UTC (or localtime when dual booting but let's not care) and never > accounts for leap seconds. Having an RTC and RTC driver behaving > differently would be

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-13 Thread Alexandre Belloni
On 13/03/2024 10:45:54+0100, Peter Hilber wrote: > > Exposing UTC as the only clock reference is bad enough; when leap > > seconds happen there's a whole second during which you don't *know* > > which second it is. It seems odd to me, for a precision clock to be > > deliberately ambiguous about

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-13 Thread Peter Hilber
On 12.03.24 18:15, David Woodhouse wrote: > On Mon, 2024-03-11 at 19:24 +0100, Peter Hilber wrote: >> On 08.03.24 13:33, David Woodhouse wrote: >>> On Fri, 2024-03-08 at 11:32 +0100, Peter Hilber wrote: On 07.03.24 15:02, David Woodhouse wrote: > Hm, should we allow UTC? If you tell me

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-12 Thread David Woodhouse
On Mon, 2024-03-11 at 19:24 +0100, Peter Hilber wrote: > On 08.03.24 13:33, David Woodhouse wrote: > > On Fri, 2024-03-08 at 11:32 +0100, Peter Hilber wrote: > > > On 07.03.24 15:02, David Woodhouse wrote: > > > > Hm, should we allow UTC? If you tell me the time in UTC, then > > > > (sometimes) I

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-11 Thread Peter Hilber
On 08.03.24 13:33, David Woodhouse wrote: > On Fri, 2024-03-08 at 11:32 +0100, Peter Hilber wrote: >> On 07.03.24 15:02, David Woodhouse wrote: >>> On Mon, 2023-12-18 at 08:38 +0100, Peter Hilber wrote: RFC v3 updates -- This series implements a driver for a

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-08 Thread David Woodhouse
On Fri, 2024-03-08 at 11:32 +0100, Peter Hilber wrote: > On 07.03.24 15:02, David Woodhouse wrote: > > On Mon, 2023-12-18 at 08:38 +0100, Peter Hilber wrote: > > > RFC v3 updates > > > -- > > > > > > This series implements a driver for a virtio-rtc device conforming to spec > > > RFC

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-08 Thread Peter Hilber
On 07.03.24 15:02, David Woodhouse wrote: > On Mon, 2023-12-18 at 08:38 +0100, Peter Hilber wrote: >> RFC v3 updates >> -- >> >> This series implements a driver for a virtio-rtc device conforming to spec >> RFC v3 [1]. It now includes an RTC class driver with alarm, in addition to >>

Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2024-03-07 Thread David Woodhouse
On Mon, 2023-12-18 at 08:38 +0100, Peter Hilber wrote: > RFC v3 updates > -- > > This series implements a driver for a virtio-rtc device conforming to spec > RFC v3 [1]. It now includes an RTC class driver with alarm, in addition to > the PTP clock driver already present before. > >

[RFC PATCH v3 0/7] Add virtio_rtc module and related changes

2023-12-17 Thread Peter Hilber
RFC v3 updates -- This series implements a driver for a virtio-rtc device conforming to spec RFC v3 [1]. It now includes an RTC class driver with alarm, in addition to the PTP clock driver already present before. This patch series depends on the patch series "treewide: Use