On Mon, Oct 18, 2021 at 08:43:31AM +0000, 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 zealci@zte.com.cn Signed-off-by: luo penghao luo.penghao@zte.com.cn

---

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 & 0x3fffff;

• 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(&dev_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);