Re: [Intel-gfx] [PATCH linux-next] drm/i915/display: Remove unused variable and its assignment.
> This one we could use. For some reason we hardcode it to > 1 now, which is correct for our use cases but I don't really> see a reason to > hardcode it here. We are supposed to calculate> it correctly after all, and > chv_crtc_clock_get() also just blindly> reads it out.> > > bestm2_frac = > crtc_state->dpll.m2 & 0x3f;> > -bestm1 = crtc_state->dpll.m1;> > This > one is a bit trickier since I don't think the spec even> gives us other > values. But we could assert that it's correct.> > Some something along these > lines I think would be best:> + drm_WARN_ON(_priv->drm, bestm1 != 2);> > vlv_dpio_write(dev_priv, pipe, CHV_PLL_DW1(port),> > DPIO_CHV_M1_DIV_BY_2 |> - 1 << DPIO_CHV_N_DIV_SHIFT);> + > bestn << DPIO_CHV_N_DIV_SHIFT); Thanks for your kind response ! Does that means the variable will be used by the hardware？if so as far as I see it, I don't seem to see the relevant interface.
Re: [Intel-gfx] [PATCH linux-next] drm/i915/display: Remove unused variable and its assignment.
> This one we could use. For some reason we hardcode it to > 1 now, which is correct for our use cases but I don't really> see a reason to > hardcode it here. We are supposed to calculate> it correctly after all, and > chv_crtc_clock_get() also just blindly> reads it out.> > > bestm2_frac = > crtc_state->dpll.m2 & 0x3f;> > -bestm1 = crtc_state->dpll.m1;> > This > one is a bit trickier since I don't think the spec even> gives us other > values. But we could assert that it's correct.> > Some something along these > lines I think would be best:> + drm_WARN_ON(_priv->drm, bestm1 != 2);> > vlv_dpio_write(dev_priv, pipe, CHV_PLL_DW1(port),> > DPIO_CHV_M1_DIV_BY_2 |> - 1 << DPIO_CHV_N_DIV_SHIFT);> + > bestn << DPIO_CHV_N_DIV_SHIFT); Thanks for your kind response ! Does that means the variable will be used by the hardware？if so as far as I see it, I don't seem to see the relevant interface.
Re: [Intel-gfx] [PATCH linux-next] drm/i915/display: Remove unused variable and its assignment.
> This one we could use. For some reason we hardcode it to > 1 now, which is correct for our use cases but I don't really> see a reason to > hardcode it here. We are supposed to calculate> it correctly after all, and > chv_crtc_clock_get() also just blindly> reads it out.> > > bestm2_frac = > crtc_state->dpll.m2 & 0x3f;> > -bestm1 = crtc_state->dpll.m1;> > This > one is a bit trickier since I don't think the spec even> gives us other > values. But we could assert that it's correct.> > Some something along these > lines I think would be best:> + drm_WARN_ON(_priv->drm, bestm1 != 2);> > vlv_dpio_write(dev_priv, pipe, CHV_PLL_DW1(port),> > DPIO_CHV_M1_DIV_BY_2 |> - 1 << DPIO_CHV_N_DIV_SHIFT);> + > bestn << DPIO_CHV_N_DIV_SHIFT); Thanks for your kind response ! Does that means the variable will be used by the hardware？if so as far as I see it, I don't seem to see the relevant interface.
[Intel-gfx] [PATCH linux-next] drm/i915/display: Remove unused variable and its assignment.
Variable is not used in functions, and its assignment is redundant too. So it should be deleted. The clang_analyzer complains as follows: drivers/gpu/drm/i915/display/intel_dpll.c:1653:2 warning: Value stored to 'bestm1' is never read. drivers/gpu/drm/i915/display/intel_dpll.c:1651:2 warning: Value stored to 'bestn' is never read. Reported-by: Zeal Robot Signed-off-by: luo penghao --- drivers/gpu/drm/i915/display/intel_dpll.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dpll.c b/drivers/gpu/drm/i915/display/intel_dpll.c index b84ed4a..28b1616 100644 --- a/drivers/gpu/drm/i915/display/intel_dpll.c +++ b/drivers/gpu/drm/i915/display/intel_dpll.c @@ -1644,13 +1644,11 @@ static void chv_prepare_pll(const struct intel_crtc_state *crtc_state) enum pipe pipe = crtc->pipe; enum dpio_channel port = vlv_pipe_to_channel(pipe); u32 loopfilter, tribuf_calcntr; - u32 bestn, bestm1, bestm2, bestp1, bestp2, bestm2_frac; + u32 bestm2, bestp1, bestp2, bestm2_frac; u32 dpio_val; int vco; - bestn = crtc_state->dpll.n; bestm2_frac = crtc_state->dpll.m2 & 0x3f; - bestm1 = crtc_state->dpll.m1; bestm2 = crtc_state->dpll.m2 >> 22; bestp1 = crtc_state->dpll.p1; bestp2 = crtc_state->dpll.p2; -- 2.15.2
Re: [Intel-gfx] [PATCH linux-next] drm/i915/display: Remove unused variable and its assignment.
On Mon, Oct 18, 2021 at 08:43:31AM +, luo penghao wrote: > Variable is not used in functions, and its assignment is redundant too. > So it should be deleted. > > The clang_analyzer complains as follows: > > drivers/gpu/drm/i915/display/intel_dpll.c:1653:2 warning: > Value stored to 'bestm1' is never read. > > drivers/gpu/drm/i915/display/intel_dpll.c:1651:2 warning: > Value stored to 'bestn' is never read. > > Reported-by: Zeal Robot > Signed-off-by: luo penghao > --- > drivers/gpu/drm/i915/display/intel_dpll.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dpll.c > b/drivers/gpu/drm/i915/display/intel_dpll.c > index b84ed4a..28b1616 100644 > --- a/drivers/gpu/drm/i915/display/intel_dpll.c > +++ b/drivers/gpu/drm/i915/display/intel_dpll.c > @@ -1644,13 +1644,11 @@ static void chv_prepare_pll(const struct > intel_crtc_state *crtc_state) > enum pipe pipe = crtc->pipe; > enum dpio_channel port = vlv_pipe_to_channel(pipe); > u32 loopfilter, tribuf_calcntr; > - u32 bestn, bestm1, bestm2, bestp1, bestp2, bestm2_frac; > + u32 bestm2, bestp1, bestp2, bestm2_frac; > u32 dpio_val; > int vco; > > - bestn = crtc_state->dpll.n; This one we could use. For some reason we hardcode it to 1 now, which is correct for our use cases but I don't really see a reason to hardcode it here. We are supposed to calculate it correctly after all, and chv_crtc_clock_get() also just blindly reads it out. > bestm2_frac = crtc_state->dpll.m2 & 0x3f; > - bestm1 = crtc_state->dpll.m1; This one is a bit trickier since I don't think the spec even gives us other values. But we could assert that it's correct. Some something along these lines I think would be best: + drm_WARN_ON(_priv->drm, bestm1 != 2); vlv_dpio_write(dev_priv, pipe, CHV_PLL_DW1(port), DPIO_CHV_M1_DIV_BY_2 | -1 << DPIO_CHV_N_DIV_SHIFT); +bestn << DPIO_CHV_N_DIV_SHIFT); -- Ville Syrjälä Intel
