gpu: nvgpu: fix coverity issues in sysfs/debugfs

Fix coverity issues in debugfs related to null check
before accessing data member.

Fix coverity issues in sysfs related to error code
over-write and unintilized error code.

coverity ids: 20087564, 20087460, 20087461
Bug 200192125

Change-Id: If82288fca18464dca7093ce10f0beb1272489609
Signed-off-by: Seshendra Gadagottu <sgadagottu@nvidia.com>
Reviewed-on: http://git-master/r/1171943
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

2 files changed, 14 insertions, 11 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/debug_gk20a.c b/drivers/gpu/nvgpu/gk20a/debug_gk20a.c
index f1e1f98a..a57a3c74 100644
--- a/drivers/gpu/nvgpu/gk20a/debug_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/debug_gk20a.c
@@ -381,22 +381,22 @@ void gk20a_debug_init(struct device *dev)
         if (platform->debugfs) {
                 platform->debugfs_alias =
                         debugfs_create_symlink("gpu.0", NULL, dev_name(dev));
-        }
 
-        debugfs_create_file("status", S_IRUGO, platform->debugfs,
+                debugfs_create_file("status", S_IRUGO, platform->debugfs,
                         dev, &gk20a_debug_fops);
-        debugfs_create_file("gr_status", S_IRUGO, platform->debugfs,
+                debugfs_create_file("gr_status", S_IRUGO, platform->debugfs,
                         dev, &gk20a_gr_debug_fops);
-        debugfs_create_u32("trace_cmdbuf", S_IRUGO|S_IWUSR, platform->debugfs,
-                        &gk20a_debug_trace_cmdbuf);
+                debugfs_create_u32("trace_cmdbuf", S_IRUGO|S_IWUSR,
+                        platform->debugfs, &gk20a_debug_trace_cmdbuf);
 
-        debugfs_create_u32("ch_wdt_timeout_ms", S_IRUGO|S_IWUSR,
+                debugfs_create_u32("ch_wdt_timeout_ms", S_IRUGO|S_IWUSR,
                         platform->debugfs, &platform->ch_wdt_timeout_ms);
 
 #if defined(GK20A_DEBUG)
-        debugfs_create_u32("dbg_mask", S_IRUGO|S_IWUSR, platform->debugfs,
-                        &gk20a_dbg_mask);
-        debugfs_create_u32("dbg_ftrace", S_IRUGO|S_IWUSR, platform->debugfs,
-                        &gk20a_dbg_ftrace);
+                debugfs_create_u32("dbg_mask", S_IRUGO|S_IWUSR,
+                        platform->debugfs, &gk20a_dbg_mask);
+                debugfs_create_u32("dbg_ftrace", S_IRUGO|S_IWUSR,
+                        platform->debugfs, &gk20a_dbg_ftrace);
 #endif
+        }
 }
diff --git a/drivers/gpu/nvgpu/gk20a/gk20a_sysfs.c b/drivers/gpu/nvgpu/gk20a/gk20a_sysfs.c
index 119030f9..127d0258 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a_sysfs.c
+++ b/drivers/gpu/nvgpu/gk20a/gk20a_sysfs.c
@@ -284,7 +284,7 @@ static ssize_t railgate_enable_store(struct device *dev,
         struct generic_pm_domain *genpd = dev_to_genpd(dev);
         struct gk20a *g = get_gk20a(dev);
         unsigned long railgate_enable = 0;
-        int err;
+        int err = 0;
 
         if (kstrtoul(buf, 10, &railgate_enable) < 0)
                 return -EINVAL;
@@ -309,6 +309,9 @@ static ssize_t railgate_enable_store(struct device *dev,
                         err = platform->unrailgate(dev);
                 mutex_unlock(&platform->railgate_lock);
         }
+        if (err)
+                return err;
+
         dev_info(dev, "railgate is %s.\n", platform->can_railgate ?
                 "enabled" : "disabled");
         /* wake-up system to make railgating_enable effective immediately */