On Thu, 2025-07-10 at 23:09 +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 <[email protected]> > > > > > --- > > > > > .../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. If I > need to use any other value I always give up immediately and just > hack the code instead.
It's unintuitive but not unusable. I have instructed several times bug reporter to set it to 0/1 to bisect if it's PSR2 problem. We have also customers using this to disable PSR modes they don't want. As we have provided this at some point I wouldn't drop it now. > > If we keep calling it 'enable_psr' then it should clearly be a > bitmask of things to *enable*, not things to *disable*. Ok, it seems I need inverse the logic to enable rather than disable. I will do that. BR, Jouni Högander > > > > > 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'. >
