gpu: nvgpu: Add L2 register read-backs following writes

LTC register write is followed by a register read
and if data doesn't match code will report the error.

Renamed existing nvgpu_writel_check function as
nvgpu_writel_loop as it loops until the write get success.

nvgpu_writel_check function write and read back and
compare the data.

Bug 2039150

Change-Id: I0a49be36aad23936f2d58aa82872710827da1d32
Signed-off-by: Vinod G <vinodg@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1762344
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/include/nvgpu/io.h b/drivers/gpu/nvgpu/include/nvgpu/io.h
index 8504829c..fb7783fe 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/io.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/io.h
@@ -40,6 +40,7 @@ void nvgpu_writel_relaxed(struct gk20a *g, u32 r, u32 v);
 u32 nvgpu_readl(struct gk20a *g, u32 r);
 u32 __nvgpu_readl(struct gk20a *g, u32 r);
 void nvgpu_writel_check(struct gk20a *g, u32 r, u32 v);
+void nvgpu_writel_loop(struct gk20a *g, u32 r, u32 v);
 void nvgpu_bar1_writel(struct gk20a *g, u32 b, u32 v);
 u32 nvgpu_bar1_readl(struct gk20a *g, u32 b);
 bool nvgpu_io_exists(struct gk20a *g);