[PATCH V5 23/25] drm/etnaviv: do not enable debug registers unconditionally

[Christian Gmeiner]

Everytime etnaviv_gpu_update_clock(..) gets call it overwrittes
the the complete VIVS_HI_CLOCK_CONTROL register. Instead read
the register, change scaling value and write the new value.

Signed-off-by: Christian Gmeiner <christian.gmeiner at gmail.com>
---
 drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
index cfe6c76d077e..10a6485a2401 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
@@ -421,8 +421,9 @@ static void etnaviv_gpu_update_clock(struct etnaviv_gpu *gpu)
 			     gpu->base_rate_shader >> gpu->freq_scale);
 	} else {
 		unsigned int fscale = 1 << (6 - gpu->freq_scale);
-		u32 clock = VIVS_HI_CLOCK_CONTROL_FSCALE_VAL(fscale);
+		u32 clock = gpu_read(gpu, VIVS_HI_CLOCK_CONTROL);
 
+		clock |= VIVS_HI_CLOCK_CONTROL_FSCALE_VAL(fscale);
 		etnaviv_gpu_load_clock(gpu, clock);
 	}
 }
-- 
2.13.5