* Can't pinctrl-baytrail be a module? @ 2016-02-11 12:45 Takashi Iwai 2016-02-11 12:56 ` Mika Westerberg 0 siblings, 1 reply; 6+ messages in thread From: Takashi Iwai @ 2016-02-11 12:45 UTC (permalink / raw) To: Mika Westerberg; +Cc: Heikki Krogerus, Linus Walleij, linux-gpio Hi, while discussing whether to enable pinctrl drivers on openSUSE distro kernels, I wonder why pinctrl-baytrail is built-in only. Basically the forced built-in is the only reason against the enablement in distro kernels. The other Intel pinctrl drivers seem to be tristate. Any missing piece there? thanks, Takashi ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Can't pinctrl-baytrail be a module? 2016-02-11 12:45 Can't pinctrl-baytrail be a module? Takashi Iwai @ 2016-02-11 12:56 ` Mika Westerberg 2016-02-11 13:08 ` Takashi Iwai 0 siblings, 1 reply; 6+ messages in thread From: Mika Westerberg @ 2016-02-11 12:56 UTC (permalink / raw) To: Takashi Iwai Cc: Heikki Krogerus, Linus Walleij, linux-gpio, Jean Delvare, Mathias Nyman +Jean and Mathias On Thu, Feb 11, 2016 at 01:45:16PM +0100, Takashi Iwai wrote: > Hi, > > while discussing whether to enable pinctrl drivers on openSUSE distro > kernels, I wonder why pinctrl-baytrail is built-in only. Basically > the forced built-in is the only reason against the enablement in > distro kernels. > > The other Intel pinctrl drivers seem to be tristate. > Any missing piece there? Jean sent a patch against this couple of hours ago. I explained to him that there is some ACPI GPIO magic happening on Baytrail-T based machines such as Asus T100 where the GPIO driver is needed early at boot, or something along those lines. I've CC'd Mathias Nyman the original author who hopefully remembers this better. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Can't pinctrl-baytrail be a module? 2016-02-11 12:56 ` Mika Westerberg @ 2016-02-11 13:08 ` Takashi Iwai 2016-02-11 13:44 ` Mathias Nyman 0 siblings, 1 reply; 6+ messages in thread From: Takashi Iwai @ 2016-02-11 13:08 UTC (permalink / raw) To: Mika Westerberg Cc: Heikki Krogerus, Linus Walleij, linux-gpio, Jean Delvare, Mathias Nyman On Thu, 11 Feb 2016 13:56:45 +0100, Mika Westerberg wrote: > > +Jean and Mathias > > On Thu, Feb 11, 2016 at 01:45:16PM +0100, Takashi Iwai wrote: > > Hi, > > > > while discussing whether to enable pinctrl drivers on openSUSE distro > > kernels, I wonder why pinctrl-baytrail is built-in only. Basically > > the forced built-in is the only reason against the enablement in > > distro kernels. > > > > The other Intel pinctrl drivers seem to be tristate. > > Any missing piece there? > > Jean sent a patch against this couple of hours ago. I noticed it right after I send my mail, too, sorry :) > I explained to him > that there is some ACPI GPIO magic happening on Baytrail-T based > machines such as Asus T100 where the GPIO driver is needed early at > boot, or something along those lines. I've CC'd Mathias Nyman the > original author who hopefully remembers this better. I know of pinctrl-cherryview is needed before others like shdci, but for Baytrail-T, it's more than that? thanks, Takashi ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Can't pinctrl-baytrail be a module? 2016-02-11 13:08 ` Takashi Iwai @ 2016-02-11 13:44 ` Mathias Nyman 2016-02-12 12:59 ` Takashi Iwai 0 siblings, 1 reply; 6+ messages in thread From: Mathias Nyman @ 2016-02-11 13:44 UTC (permalink / raw) To: Takashi Iwai, Mika Westerberg Cc: Heikki Krogerus, Linus Walleij, linux-gpio, Jean Delvare On 11.02.2016 15:08, Takashi Iwai wrote: > On Thu, 11 Feb 2016 13:56:45 +0100, > Mika Westerberg wrote: >> >> +Jean and Mathias >> >> On Thu, Feb 11, 2016 at 01:45:16PM +0100, Takashi Iwai wrote: >>> Hi, >>> >>> while discussing whether to enable pinctrl drivers on openSUSE distro >>> kernels, I wonder why pinctrl-baytrail is built-in only. Basically >>> the forced built-in is the only reason against the enablement in >>> distro kernels. >>> >>> The other Intel pinctrl drivers seem to be tristate. >>> Any missing piece there? >> >> Jean sent a patch against this couple of hours ago. > > I noticed it right after I send my mail, too, sorry :) > >> I explained to him >> that there is some ACPI GPIO magic happening on Baytrail-T based >> machines such as Asus T100 where the GPIO driver is needed early at >> boot, or something along those lines. I've CC'd Mathias Nyman the >> original author who hopefully remembers this better. > > I know of pinctrl-cherryview is needed before others like shdci, but > for Baytrail-T, it's more than that? > If I remember correctly the reason was that the gpio driver was supposed to work with Hardware reduced ACPI events (in ACPI 5). Basically ACPI telling operating system it wants an ACPI event handler run when a certain gpio interrupt is triggered, and the HW reduced ACPI expects the OS gpio driver to do it. I haven't followed up on this at all. Can't say if we have any HW reduced baytrail variants out there. For Lynxpoint there was also some issue that pnpacpi reserved the IO resources before a modular gpio driver could get it, I think it was fixed, might be that baytrail would face same issue. -Mathias ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Can't pinctrl-baytrail be a module? 2016-02-11 13:44 ` Mathias Nyman @ 2016-02-12 12:59 ` Takashi Iwai 2016-08-02 8:38 ` Jean Delvare 0 siblings, 1 reply; 6+ messages in thread From: Takashi Iwai @ 2016-02-12 12:59 UTC (permalink / raw) To: Mathias Nyman Cc: Mika Westerberg, Heikki Krogerus, Linus Walleij, linux-gpio, Jean Delvare On Thu, 11 Feb 2016 14:44:28 +0100, Mathias Nyman wrote: > > On 11.02.2016 15:08, Takashi Iwai wrote: > > On Thu, 11 Feb 2016 13:56:45 +0100, > > Mika Westerberg wrote: > >> > >> +Jean and Mathias > >> > >> On Thu, Feb 11, 2016 at 01:45:16PM +0100, Takashi Iwai wrote: > >>> Hi, > >>> > >>> while discussing whether to enable pinctrl drivers on openSUSE distro > >>> kernels, I wonder why pinctrl-baytrail is built-in only. Basically > >>> the forced built-in is the only reason against the enablement in > >>> distro kernels. > >>> > >>> The other Intel pinctrl drivers seem to be tristate. > >>> Any missing piece there? > >> > >> Jean sent a patch against this couple of hours ago. > > > > I noticed it right after I send my mail, too, sorry :) > > > >> I explained to him > >> that there is some ACPI GPIO magic happening on Baytrail-T based > >> machines such as Asus T100 where the GPIO driver is needed early at > >> boot, or something along those lines. I've CC'd Mathias Nyman the > >> original author who hopefully remembers this better. > > > > I know of pinctrl-cherryview is needed before others like shdci, but > > for Baytrail-T, it's more than that? > > > > If I remember correctly the reason was that the gpio driver was supposed > to work with Hardware reduced ACPI events (in ACPI 5). > Basically ACPI telling operating system it wants an ACPI event handler run > when a certain gpio interrupt is triggered, and the HW reduced ACPI expects the OS gpio driver to do it. OK, so this is an implicit dependency. If this is the only issue, it sounds like the driver can be a module. > I haven't followed up on this at all. Can't say if we have any HW reduced baytrail variants out there. > > For Lynxpoint there was also some issue that pnpacpi reserved the IO resources before a modular gpio driver could get it, > I think it was fixed, might be that baytrail would face same issue. Could you give any pointer, if you remember? Thanks! Takashi ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Can't pinctrl-baytrail be a module? 2016-02-12 12:59 ` Takashi Iwai @ 2016-08-02 8:38 ` Jean Delvare 0 siblings, 0 replies; 6+ messages in thread From: Jean Delvare @ 2016-08-02 8:38 UTC (permalink / raw) To: Mathias Nyman Cc: Takashi Iwai, Mika Westerberg, Heikki Krogerus, Linus Walleij, linux-gpio On Fri, 12 Feb 2016 13:59:45 +0100, Takashi Iwai wrote: > On Thu, 11 Feb 2016 14:44:28 +0100, > Mathias Nyman wrote: > > > > On 11.02.2016 15:08, Takashi Iwai wrote: > > > On Thu, 11 Feb 2016 13:56:45 +0100, > > > Mika Westerberg wrote: > > >> > > >> +Jean and Mathias > > >> > > >> On Thu, Feb 11, 2016 at 01:45:16PM +0100, Takashi Iwai wrote: > > >>> Hi, > > >>> > > >>> while discussing whether to enable pinctrl drivers on openSUSE distro > > >>> kernels, I wonder why pinctrl-baytrail is built-in only. Basically > > >>> the forced built-in is the only reason against the enablement in > > >>> distro kernels. > > >>> > > >>> The other Intel pinctrl drivers seem to be tristate. > > >>> Any missing piece there? > > >> > > >> Jean sent a patch against this couple of hours ago. > > > > > > I noticed it right after I send my mail, too, sorry :) > > > > > >> I explained to him > > >> that there is some ACPI GPIO magic happening on Baytrail-T based > > >> machines such as Asus T100 where the GPIO driver is needed early at > > >> boot, or something along those lines. I've CC'd Mathias Nyman the > > >> original author who hopefully remembers this better. > > > > > > I know of pinctrl-cherryview is needed before others like shdci, but > > > for Baytrail-T, it's more than that? > > > > > > > If I remember correctly the reason was that the gpio driver was supposed > > to work with Hardware reduced ACPI events (in ACPI 5). > > Basically ACPI telling operating system it wants an ACPI event handler run > > when a certain gpio interrupt is triggered, and the HW reduced ACPI expects the OS gpio driver to do it. > > OK, so this is an implicit dependency. If this is the only issue, it > sounds like the driver can be a module. > > > I haven't followed up on this at all. Can't say if we have any HW reduced baytrail variants out there. > > > > For Lynxpoint there was also some issue that pnpacpi reserved the IO resources before a modular gpio driver could get it, > > I think it was fixed, might be that baytrail would face same issue. > > Could you give any pointer, if you remember? Mathias, any progress on this? Thanks, -- Jean Delvare SUSE L3 Support ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2016-08-02 8:38 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2016-02-11 12:45 Can't pinctrl-baytrail be a module? Takashi Iwai 2016-02-11 12:56 ` Mika Westerberg 2016-02-11 13:08 ` Takashi Iwai 2016-02-11 13:44 ` Mathias Nyman 2016-02-12 12:59 ` Takashi Iwai 2016-08-02 8:38 ` Jean Delvare
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