[Nouveau] [PATCH v2] drm/nouveau/clk: fix tstate to pstate calculation

[Wei Ni]

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 at nvidia.com>
---
v2: create patch based on http://cgit.freedesktop.org/~darktama/nouveau/

 drm/nouveau/nvkm/subdev/clk/base.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drm/nouveau/nvkm/subdev/clk/base.c b/drm/nouveau/nvkm/subdev/clk/base.c
index 39a83d82e0cd..77a0ab5ca3b0 100644
--- a/drm/nouveau/nvkm/subdev/clk/base.c
+++ b/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;
-- 
1.9.1