3 files changed, 21 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.h b/drivers/gpu/nvgpu/gk20a/gk20a.h
index 081ec077..f16be5a1 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.h
@@ -84,6 +84,7 @@ struct gpu_ops {
                 void (*init_fs_state)(struct gk20a *g);
                 void (*elpg_flush)(struct gk20a *g);
                 void (*isr)(struct gk20a *g);
+                u32 (*cbc_fix_config)(struct gk20a *g, int base);
         } ltc;
         struct {
                 int (*init_fs_state)(struct gk20a *g);
diff --git a/drivers/gpu/nvgpu/gk20a/ltc_common.c b/drivers/gpu/nvgpu/gk20a/ltc_common.c
index 72477983..75530b25 100644
--- a/drivers/gpu/nvgpu/gk20a/ltc_common.c
+++ b/drivers/gpu/nvgpu/gk20a/ltc_common.c
@@ -291,7 +291,7 @@ static void gk20a_ltc_init_cbc(struct gk20a *g, struct gr_gk20a *gr)
         compbit_base_post_divide64 = compbit_store_base_iova >>
                 ltc_ltcs_ltss_cbc_base_alignment_shift_v();
 
-        do_div(compbit_base_post_divide64, gr->num_fbps);
+        do_div(compbit_base_post_divide64, g->ltc_count);
         compbit_base_post_divide = u64_lo32(compbit_base_post_divide64);
 
         compbit_base_post_multiply64 = ((u64)compbit_base_post_divide *
@@ -300,6 +300,11 @@ static void gk20a_ltc_init_cbc(struct gk20a *g, struct gr_gk20a *gr)
         if (compbit_base_post_multiply64 < compbit_store_base_iova)
                 compbit_base_post_divide++;
 
+        /* Bug 1477079 indicates sw adjustment on the posted divided base. */
+        if (g->ops.ltc.cbc_fix_config)
+                compbit_base_post_divide =
+                        g->ops.ltc.cbc_fix_config(g, compbit_base_post_divide);
+
         gk20a_writel(g, ltc_ltcs_ltss_cbc_base_r(),
                 compbit_base_post_divide);
 
diff --git a/drivers/gpu/nvgpu/gm20b/ltc_gm20b.c b/drivers/gpu/nvgpu/gm20b/ltc_gm20b.c
index 43c90970..91046d93 100644
--- a/drivers/gpu/nvgpu/gm20b/ltc_gm20b.c
+++ b/drivers/gpu/nvgpu/gm20b/ltc_gm20b.c
@@ -237,6 +237,19 @@ static void gm20b_ltc_g_elpg_flush_locked(struct gk20a *g)
                             "g_elpg_flush too many retries");
 }
 
+u32 gm20b_ltc_cbc_fix_config(struct gk20a *g, int base)
+{
+        u32 val = gk20a_readl(g, ltc_ltcs_ltss_cbc_num_active_ltcs_r());
+        if (val == 2) {
+                return base * 2;
+        } else if (val != 1) {
+                gk20a_err(dev_from_gk20a(g),
+                        "Invalid number of active ltcs: %08x\n", val);
+        }
+
+        return base;
+}
+
 void gm20b_init_ltc(struct gpu_ops *gops)
 {
         /* Gk20a reused ops. */
@@ -255,4 +268,5 @@ void gm20b_init_ltc(struct gpu_ops *gops)
         gops->ltc.cbc_ctrl = gm20b_ltc_cbc_ctrl;
         gops->ltc.elpg_flush = gm20b_ltc_g_elpg_flush_locked;
         gops->ltc.isr = gm20b_ltc_isr;
+        gops->ltc.cbc_fix_config = gm20b_ltc_cbc_fix_config;
 }