drm/nouveau/drm/nouveau/clk: fix tstate to pstate calculation

According to the tstate calculation in nvkm_clk_tstate(),
the range of tstate is from -(clk->state_nr - 1) to 0,
it mean the tstate is negative value. But in nvkm_pstate_work(),
it use (clk->state_nr - 1 - clk->tstate) to limit pstate,
it's not correct.
This patch fix it to use (clk->state_nr - 1 + clk->tstate) to
limit pstate.

Signed-off-by: Wei Ni <wni@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/base.c
index 39a83d8..77a0ab5 100644 (file)
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/base.c
@@ -214,7 +214,7 @@ nvkm_pstate_work(struct work_struct *work)
        pstate = clk->pwrsrc ? clk->ustate_ac : clk->ustate_dc;
        if (clk->state_nr && pstate != -1) {
                pstate = (pstate < 0) ? clk->astate : pstate;
-               pstate = min(pstate, clk->state_nr - 1 - clk->tstate);
+               pstate = min(pstate, clk->state_nr - 1 + clk->tstate);
                pstate = max(pstate, clk->dstate);
        } else {
                pstate = clk->pstate = -1;