On Thu, Jul 10, 2025 at 05:27:13PM -0400, Rodrigo Vivi wrote: > On Thu, Jul 10, 2025 at 11:09:42PM +0300, Ville Syrjälä wrote: > > On Thu, Jul 10, 2025 at 11:42:52AM -0400, Rodrigo Vivi wrote: > > > On Wed, Jul 09, 2025 at 06:11:17PM +0000, Hogander, Jouni wrote: > > > > On Wed, 2025-07-09 at 20:03 +0300, Ville Syrjälä wrote: > > > > > On Wed, Jul 09, 2025 at 10:57:58AM +0300, Jouni Högander wrote: > > > > > > Currently disabling PSR2 via enable_psr module parameter causes > > > > > > Panel > > > > > > Replay being disabled as well. This patch changes this by still > > > > > > allowing > > > > > > Panel Replay even if PSR2 is disabled. > > > > > > > > > > > > After this patch enable_psr module parameter values are: > > > > > > > > > > > > -1 = PSR1 : yes, PSR2 = yes, Panel Replay : yes > > > > > > 0 = PSR1 : no, PSR2 = no, Panel Replay : no > > > > > > 1 = PSR1 : yes, PSR2 = no, Panel Replay : yes > > > > > > 2 = PSR1 : yes, PSR2 = yes, Panel Replay : no > > > > > > 3 = PSR1 : yes, PSR2 = no, Panel Replay : no > > > > > > > > > > > > I.e. values different than -1 and 0 are handled as bitmasks where > > > > > > BIT0 > > > > > > disables PSR2 and BIT1 disables Panel Replay. > > > > > > > > > > > > v2: > > > > > > - make it more clear that enable_psr is bitmask for disabling > > > > > > different > > > > > > PSR modes > > > > > > > > > > > > Signed-off-by: Jouni Högander <jouni.hogan...@intel.com> > > > > > > --- > > > > > > .../drm/i915/display/intel_display_params.c | 6 ++--- > > > > > > drivers/gpu/drm/i915/display/intel_psr.c | 22 ++++++++++++++- > > > > > > ---- > > > > > > 2 files changed, 19 insertions(+), 9 deletions(-) > > > > > > > > > > > > diff --git a/drivers/gpu/drm/i915/display/intel_display_params.c > > > > > > b/drivers/gpu/drm/i915/display/intel_display_params.c > > > > > > index 75316247ee8a..195af19ece5f 100644 > > > > > > --- a/drivers/gpu/drm/i915/display/intel_display_params.c > > > > > > +++ b/drivers/gpu/drm/i915/display/intel_display_params.c > > > > > > @@ -116,9 +116,9 @@ intel_display_param_named_unsafe(enable_fbc, > > > > > > int, 0400, > > > > > > "(default: -1 (use per-chip default))"); > > > > > > > > > > > > intel_display_param_named_unsafe(enable_psr, int, 0400, > > > > > > - "Enable PSR " > > > > > > - "(0=disabled, 1=enable up to PSR1, 2=enable up to PSR2) " > > > > > > - "Default: -1 (use per-chip default)"); > > > > > > + "Enable PSR (0=disabled, 1=disable PSR2 (BIT0), 2=disable > > > > > > Panel Replay (BIT1))." > > > > > > + "Values different from 0 and -1 are handled as bitmask to > > > > > > disable different PSR modes." > > > > > > + "E.g. value 3 disables both PSR2 and Panel Replay. > > > > > > Default: -1 (use per-chip default)"); > > > > > > > > > > This thing is very unintuitive. Why don't we just get replace it > > > > > with a new disable_psr modparam that is clearly just a bitmask of > > > > > what to disable? > > > > > > > > I was thinkinig we should keep it backward compatible. I know this > > > > parameter is in use. > > > > > > I agree on keeping this backward compatible. > > > > IMO it's an unusable mess so I wouldn't bother trying to preserve it. > > The only value that seems to make any sense currently is =0. > > fair enough. what about simply removing all the options entirely? > enable_psr=0 keeps disabling it, otherwise enabled it. And we reduce > all the knobs option. Afterall, this should be our end goal anyway. > > > If I > > need to use any other value I always give up immediately and just > > hack the code instead. > > Well, the param actually exists for us to request reporters to try > different config. The devs can always modify the code. > > Question now is, are all these variants useful for collecting debug > information of some sort? > > If so, as long as it is documented and we can ask different values, > we should be good. > > > > > If we keep calling it 'enable_psr' then it should clearly be a > > bitmask of things to *enable*, not things to *disable*. > > > > > > > > Also our experience with disable_power_well shows that negative > > > name in the parameter can be much more unintuitive and confusing. > > > > That one is rather different because it doesn't "disable power wells" > > but rather it "disables power well disabling". But yes, it is a very > > poor name as well. > > > > Calling it "enable_power_wells" wouldn't really help though. > > It should perhaps be something more like 'dont_disable_power_wells' > > or 'keep_power_wells_on'. > > okay, fair enough, disable power well is another level of complication. > > back to disable_psr idea: > > disable_psr=0 == enable PSR? to me this is already uninituitive anyway. > disable_psr=1 == disable PSR1? > disable_psr=2 == disable PSR2? and keep only PSR=1? > > I still don't see a clean obvious intuitive way of handling it. > Perhaps what I had suggested another day: > > PSR1 = BIT0 > PSR2 = BIT1 (PSR2 infers PSR1 enabled) > PANEL_REPLAY = BIT2 (also infers PSR1(and 2?) enabled)
With a bitmask I don't think inferring anything is helpful. If the corresponding bit isn't set then don't use that mode, period. Another option would to have a separate named parameter for each mode. Would be easier to understand but dunno if we really want to add that many modparams just for this. > (Peraps even bit3 for early transport?) > > This is backwards compatible because > > 0 = disabled, > 1 = up to psr1, > 2 = up to psr2, (no panel replay) > 3 = up to psr2, (same as 2) > 4 = panel replay on > ... > > > > > -- > > Ville Syrjälä > > Intel -- Ville Syrjälä Intel
