Re: [systemd-devel] systemd-backlight and backlight level 0
On Wed, 05.03.14 11:31, Josh Triplett (j...@joshtriplett.org) wrote: On restore, I'd suggest reading max_brightness, and if the stored value falls under a threshold of ceil(max_brightness/SOME_DIVISOR), restore it to that value instead. (Ideally there should be some way to ask the driver what level of brightness will produce a non-zero value in actual_brightness, but no such mechanism seems to exist.) Does that sound reasonable? I'd be willing to merge that on ignore put the brightness to at least 1 or 5% of the full range, for whatever is larger. i.e. MAX(1, max_brightness/20). Lennart -- Lennart Poettering, Red Hat ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
[systemd-devel] systemd-backlight and backlight level 0
systemd-backlight saves backlight levels on shutdown, and restores them on startup. However, on some systems, backlight level 0 actually turns the backlight *off*; this can potentially make the system unusable. Complicating matters, on most systems, nothing pays attention to the brightness adjustment keys in text mode. I'd suggest one or both of the following two changes, to avoid a painful failure mode: - systemd-backlight should avoid saving/restoring a backlight level of 0, and have a minimum backlight level. (Possibly overridable via configuration, for people who *really* want to restore backlight level 0.) - Something ought to listen to the brightness keys (and perhaps other hotkeys) in pure text mode. systemd seems like a good place for such a something to live. - Josh Triplett ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] systemd-backlight and backlight level 0
Hi On Wed, Mar 5, 2014 at 6:46 PM, Josh Triplett j...@joshtriplett.org wrote: systemd-backlight saves backlight levels on shutdown, and restores them on startup. However, on some systems, backlight level 0 actually turns the backlight *off*; this can potentially make the system unusable. Complicating matters, on most systems, nothing pays attention to the brightness adjustment keys in text mode. I'd suggest one or both of the following two changes, to avoid a painful failure mode: - systemd-backlight should avoid saving/restoring a backlight level of 0, and have a minimum backlight level. (Possibly overridable via configuration, for people who *really* want to restore backlight level 0.) Never restoring val==0 seems fine to me. - Something ought to listen to the brightness keys (and perhaps other hotkeys) in pure text mode. systemd seems like a good place for such a something to live. We cannot do that. It requires keymap-handling (as brightness keys are handled on the keysym, not keycode level) and this is exclusive territory of the compositor (or other foreground session controllers). Thanks David ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] systemd-backlight and backlight level 0
On Wed, 05.03.14 09:46, Josh Triplett (j...@joshtriplett.org) wrote: systemd-backlight saves backlight levels on shutdown, and restores them on startup. However, on some systems, backlight level 0 actually turns the backlight *off*; this can potentially make the system unusable. Complicating matters, on most systems, nothing pays attention to the brightness adjustment keys in text mode. I'd suggest one or both of the following two changes, to avoid a painful failure mode: - systemd-backlight should avoid saving/restoring a backlight level of 0, and have a minimum backlight level. (Possibly overridable via configuration, for people who *really* want to restore backlight level 0.) To deal with situations like this there's systemd.restore_state=0 on the kernel cmdline, see kernel-command-line(7). I could be convinced to fix brightness level 0 to 1 when restoring. But then again, I fear the next people will come then and say 1 is only marginally better than 0, i want the minimum to be 16!... Or even others saying Dude, I only got 3 brightness levels, and you took one away from me So I am not enthusiastic about the idea... - Something ought to listen to the brightness keys (and perhaps other hotkeys) in pure text mode. systemd seems like a good place for such a something to live. That's definitely a job for the DE I am sure, so that can it do an OSD and all the other stuff. We do power button handling in logind only because what it does is relatively important and really close to the system lifecycle... But brightness keys (or volume keys..) are not close at all. I am really sure that that's for the DEs to handle, not us. Lennart -- Lennart Poettering, Red Hat ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] systemd-backlight and backlight level 0
On Wed, Mar 05, 2014 at 06:59:27PM +0100, David Herrmann wrote: On Wed, Mar 5, 2014 at 6:46 PM, Josh Triplett j...@joshtriplett.org wrote: systemd-backlight saves backlight levels on shutdown, and restores them on startup. However, on some systems, backlight level 0 actually turns the backlight *off*; this can potentially make the system unusable. Complicating matters, on most systems, nothing pays attention to the brightness adjustment keys in text mode. I'd suggest one or both of the following two changes, to avoid a painful failure mode: - systemd-backlight should avoid saving/restoring a backlight level of 0, and have a minimum backlight level. (Possibly overridable via configuration, for people who *really* want to restore backlight level 0.) Never restoring val==0 seems fine to me. Likewise. - Something ought to listen to the brightness keys (and perhaps other hotkeys) in pure text mode. systemd seems like a good place for such a something to live. We cannot do that. It requires keymap-handling (as brightness keys are handled on the keysym, not keycode level) and this is exclusive territory of the compositor (or other foreground session controllers). Perhaps this will get fixed when we switch from kernel VTs to a userspace-managed console, then. - Josh Triplett ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] systemd-backlight and backlight level 0
On Wed, Mar 05, 2014 at 07:10:51PM +0100, Lennart Poettering wrote: On Wed, 05.03.14 09:46, Josh Triplett (j...@joshtriplett.org) wrote: systemd-backlight saves backlight levels on shutdown, and restores them on startup. However, on some systems, backlight level 0 actually turns the backlight *off*; this can potentially make the system unusable. Complicating matters, on most systems, nothing pays attention to the brightness adjustment keys in text mode. I'd suggest one or both of the following two changes, to avoid a painful failure mode: - systemd-backlight should avoid saving/restoring a backlight level of 0, and have a minimum backlight level. (Possibly overridable via configuration, for people who *really* want to restore backlight level 0.) To deal with situations like this there's systemd.restore_state=0 on the kernel cmdline, see kernel-command-line(7). Yeah, I've seen that one; however, having to reboot the system and change the kernel command line to unbreak it seems less ideal than having the system avoid broken states to begin with. I could be convinced to fix brightness level 0 to 1 when restoring. But then again, I fear the next people will come then and say 1 is only marginally better than 0, i want the minimum to be 16!... Or even others saying Dude, I only got 3 brightness levels, and you took one away from me So I am not enthusiastic about the idea... Given the choice between maximum flexibility and never making the system unusable, I'll take the latter. Not that hard to make it configurable, if that proves necessary. On restore, I'd suggest reading max_brightness, and if the stored value falls under a threshold of ceil(max_brightness/SOME_DIVISOR), restore it to that value instead. (Ideally there should be some way to ask the driver what level of brightness will produce a non-zero value in actual_brightness, but no such mechanism seems to exist.) Does that sound reasonable? - Something ought to listen to the brightness keys (and perhaps other hotkeys) in pure text mode. systemd seems like a good place for such a something to live. That's definitely a job for the DE I am sure, so that can it do an OSD and all the other stuff. We do power button handling in logind only because what it does is relatively important and really close to the system lifecycle... But brightness keys (or volume keys..) are not close at all. I am really sure that that's for the DEs to handle, not us. DEs don't handle the text consoles. However, it does sound like this will have to wait for kmscon or equivalent. - Josh Triplett ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] systemd-backlight and backlight level 0
Hi On Wed, Mar 5, 2014 at 8:31 PM, Josh Triplett j...@joshtriplett.org wrote: On Wed, Mar 05, 2014 at 07:10:51PM +0100, Lennart Poettering wrote: On Wed, 05.03.14 09:46, Josh Triplett (j...@joshtriplett.org) wrote: systemd-backlight saves backlight levels on shutdown, and restores them on startup. However, on some systems, backlight level 0 actually turns the backlight *off*; this can potentially make the system unusable. Complicating matters, on most systems, nothing pays attention to the brightness adjustment keys in text mode. I'd suggest one or both of the following two changes, to avoid a painful failure mode: - systemd-backlight should avoid saving/restoring a backlight level of 0, and have a minimum backlight level. (Possibly overridable via configuration, for people who *really* want to restore backlight level 0.) To deal with situations like this there's systemd.restore_state=0 on the kernel cmdline, see kernel-command-line(7). Yeah, I've seen that one; however, having to reboot the system and change the kernel command line to unbreak it seems less ideal than having the system avoid broken states to begin with. I'd expect this to be set on the recovery boot option. At I know some distros always provide two boot entries and to me this seems like the right place to set it. I could be convinced to fix brightness level 0 to 1 when restoring. But then again, I fear the next people will come then and say 1 is only marginally better than 0, i want the minimum to be 16!... Or even others saying Dude, I only got 3 brightness levels, and you took one away from me So I am not enthusiastic about the idea... Given the choice between maximum flexibility and never making the system unusable, I'll take the latter. Not that hard to make it configurable, if that proves necessary. On restore, I'd suggest reading max_brightness, and if the stored value falls under a threshold of ceil(max_brightness/SOME_DIVISOR), restore it to that value instead. (Ideally there should be some way to ask the driver what level of brightness will produce a non-zero value in actual_brightness, but no such mechanism seems to exist.) Does that sound reasonable? - Something ought to listen to the brightness keys (and perhaps other hotkeys) in pure text mode. systemd seems like a good place for such a something to live. That's definitely a job for the DE I am sure, so that can it do an OSD and all the other stuff. We do power button handling in logind only because what it does is relatively important and really close to the system lifecycle... But brightness keys (or volume keys..) are not close at all. I am really sure that that's for the DEs to handle, not us. DEs don't handle the text consoles. However, it does sound like this will have to wait for kmscon or equivalent. Yepp. Thanks David ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] systemd-backlight and backlight level 0
On Wed, Mar 05, 2014 at 10:21:17PM +0100, David Herrmann wrote: On Wed, Mar 5, 2014 at 8:31 PM, Josh Triplett j...@joshtriplett.org wrote: On Wed, Mar 05, 2014 at 07:10:51PM +0100, Lennart Poettering wrote: On Wed, 05.03.14 09:46, Josh Triplett (j...@joshtriplett.org) wrote: systemd-backlight saves backlight levels on shutdown, and restores them on startup. However, on some systems, backlight level 0 actually turns the backlight *off*; this can potentially make the system unusable. Complicating matters, on most systems, nothing pays attention to the brightness adjustment keys in text mode. I'd suggest one or both of the following two changes, to avoid a painful failure mode: - systemd-backlight should avoid saving/restoring a backlight level of 0, and have a minimum backlight level. (Possibly overridable via configuration, for people who *really* want to restore backlight level 0.) To deal with situations like this there's systemd.restore_state=0 on the kernel cmdline, see kernel-command-line(7). Yeah, I've seen that one; however, having to reboot the system and change the kernel command line to unbreak it seems less ideal than having the system avoid broken states to begin with. I'd expect this to be set on the recovery boot option. At I know some distros always provide two boot entries and to me this seems like the right place to set it. Not a bad idea, but rather than requiring the addition of an extra option (or potentially more than one, if other parts of systemd might want to be more conservative on recovery as well), how about having systemd-backlight treat single as systemd.restore_state=0? - Josh Triplett ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
