diff --git a/drivers/gpu/drm/tegra/gr2d.c b/drivers/gpu/drm/tegra/gr2d.c
index a936902..c3ded60 100644
--- a/drivers/gpu/drm/tegra/gr2d.c
+++ b/drivers/gpu/drm/tegra/gr2d.c
@@ -131,6 +131,14 @@ static int gr2d_submit(struct tegra_drm_context
*context,
                if (err)
                        goto fail;

+               /* We define CMA as an temporary solution in host1x driver.
+                  That's also why we have a CMA kernel config in it.
+                  But seems here, in tegradrm, we hardcode the CMA here.
+                  So what do you do when host1x change to IOMMU?
+                  Do we also need to define a CMA config in tegradrm
driver,
+                  then after host1x changes to IOMMU, we add another IOMMU
+                  config in tegradrm? Or we should invent another more
+                  generic wrapper layer here? */
                cmdbuf.mem = handle_cma_to_host1x(drm, file_priv,
cmdbuf.mem);
                if (!cmdbuf.mem)
                        goto fail;
diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c
index cc8ca2f..0867b72 100644
--- a/drivers/gpu/host1x/job.c
+++ b/drivers/gpu/host1x/job.c
@@ -82,6 +82,26 @@ struct host1x_job *host1x_job_alloc(struct
host1x_channel *ch,
        mem += num_unpins * sizeof(dma_addr_t);
        job->pin_ids = num_unpins ? mem : NULL;

+       /* I think this is a somewhat ugly design.
+          Actually "addr_phys" is consisted by "reloc_addr_phys" and
+          "gather_addr_phys".
+          Why don't we just declare "reloc_addr_phys" and
"gather_addr_phys"?
+          In current design, let's say if one nvhost newbie changes the
order
+          of these 2 blocks of code in function "pin_job_mem":
+
+          for (i = 0; i < job->num_relocs; i++) {
+               struct host1x_reloc *reloc = &job->relocarray[i];
+               job->pin_ids[count] = reloc->target;
+               count++;
+          }
+
+          for (i = 0; i < job->num_gathers; i++) {
+               struct host1x_job_gather *g = &job->gathers[i];
+               job->pin_ids[count] = g->mem_id;
+               count++;
+          }
+
+          Then likely something weird occurs... */
        job->reloc_addr_phys = job->addr_phys;
        job->gather_addr_phys = &job->addr_phys[num_relocs];

@@ -252,6 +272,10 @@ static int do_relocs(struct host1x_job *job,
                        }
                }

+               /* I have question here. Does this mean the address info
+                  which need to be relocated(according to the libdrm codes,
+                  seems this address is "0xDEADBEEF") always staying at the
+                  beginning of a page? */
                __raw_writel(
                        (job->reloc_addr_phys[i] +
                                reloc->target_offset) >> reloc->shift,
@@ -565,6 +589,7 @@ int host1x_job_pin(struct host1x_job *job, struct
platform_device *pdev)
                }
        }

+       /* if (host1x_firewall && !err) { */
        if (host1x_firewall) {
                err = copy_gathers(job, pdev);
                if (err) {
@@ -573,6 +598,9 @@ int host1x_job_pin(struct host1x_job *job, struct
platform_device *pdev)
                }
        }

+/* Rename this label to "out" or something else.
+   Because if everything goes right, the codes under this label also
+   get executed. */
 fail:
        wmb();

diff --git a/drivers/gpu/host1x/memmgr.c b/drivers/gpu/host1x/memmgr.c
index f3954f7..bb5763d 100644
--- a/drivers/gpu/host1x/memmgr.c
+++ b/drivers/gpu/host1x/memmgr.c
@@ -156,6 +156,9 @@ int host1x_memmgr_pin_array_ids(struct
platform_device *dev,
                        count, &unpin_data[pin_count],
                        phys_addr);

+               /* I don't think the current "host1x_cma_pin_array_ids"
+                  is able to return a negative value. So this "if" doesn't
+                  make sense...*/
                if (cma_count < 0) {
                        /* clean up previous handles */