[PATCH] drm/amd/display: drop unnecessary NULL checks in debugfs

Alexey Kodanev aleksei.kodanev at bell-sw.com
Tue Dec 27 17:04:15 UTC 2022


pipe_ctx pointer cannot be NULL when getting the address of
an element of the pipe_ctx array. Moreover, the MAX_PIPES is
defined as 6, so pipe_ctx is not NULL after the loop either.

Detected using the static analysis tool - Svace.
Signed-off-by: Alexey Kodanev <aleksei.kodanev at bell-sw.com>
---
 .../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 72 +++++--------------
 1 file changed, 16 insertions(+), 56 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
index 461037a3dd75..cec16eaf2fb0 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
@@ -1375,16 +1375,11 @@ static ssize_t dp_dsc_clock_en_read(struct file *f, char __user *buf,
 
 	for (i = 0; i < MAX_PIPES; i++) {
 		pipe_ctx = &aconnector->dc_link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream &&
+		if (pipe_ctx->stream &&
 		    pipe_ctx->stream->link == aconnector->dc_link)
 			break;
 	}
 
-	if (!pipe_ctx) {
-		kfree(rd_buf);
-		return -ENXIO;
-	}
-
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
 		dsc->funcs->dsc_read_state(dsc, &dsc_state);
@@ -1481,12 +1476,12 @@ static ssize_t dp_dsc_clock_en_write(struct file *f, const char __user *buf,
 
 	for (i = 0; i < MAX_PIPES; i++) {
 		pipe_ctx = &aconnector->dc_link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream &&
+		if (pipe_ctx->stream &&
 		    pipe_ctx->stream->link == aconnector->dc_link)
 			break;
 	}
 
-	if (!pipe_ctx || !pipe_ctx->stream)
+	if (!pipe_ctx->stream)
 		goto done;
 
 	// Get CRTC state
@@ -1566,16 +1561,11 @@ static ssize_t dp_dsc_slice_width_read(struct file *f, char __user *buf,
 
 	for (i = 0; i < MAX_PIPES; i++) {
 		pipe_ctx = &aconnector->dc_link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream &&
+		if (pipe_ctx->stream &&
 		    pipe_ctx->stream->link == aconnector->dc_link)
 			break;
 	}
 
-	if (!pipe_ctx) {
-		kfree(rd_buf);
-		return -ENXIO;
-	}
-
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
 		dsc->funcs->dsc_read_state(dsc, &dsc_state);
@@ -1670,12 +1660,12 @@ static ssize_t dp_dsc_slice_width_write(struct file *f, const char __user *buf,
 
 	for (i = 0; i < MAX_PIPES; i++) {
 		pipe_ctx = &aconnector->dc_link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream &&
+		if (pipe_ctx->stream &&
 		    pipe_ctx->stream->link == aconnector->dc_link)
 			break;
 	}
 
-	if (!pipe_ctx || !pipe_ctx->stream)
+	if (!pipe_ctx->stream)
 		goto done;
 
 	// Safely get CRTC state
@@ -1755,16 +1745,11 @@ static ssize_t dp_dsc_slice_height_read(struct file *f, char __user *buf,
 
 	for (i = 0; i < MAX_PIPES; i++) {
 		pipe_ctx = &aconnector->dc_link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream &&
+		if (pipe_ctx->stream &&
 		    pipe_ctx->stream->link == aconnector->dc_link)
 			break;
 	}
 
-	if (!pipe_ctx) {
-		kfree(rd_buf);
-		return -ENXIO;
-	}
-
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
 		dsc->funcs->dsc_read_state(dsc, &dsc_state);
@@ -1859,12 +1844,12 @@ static ssize_t dp_dsc_slice_height_write(struct file *f, const char __user *buf,
 
 	for (i = 0; i < MAX_PIPES; i++) {
 		pipe_ctx = &aconnector->dc_link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream &&
+		if (pipe_ctx->stream &&
 		    pipe_ctx->stream->link == aconnector->dc_link)
 			break;
 	}
 
-	if (!pipe_ctx || !pipe_ctx->stream)
+	if (!pipe_ctx->stream)
 		goto done;
 
 	// Get CRTC state
@@ -1940,16 +1925,11 @@ static ssize_t dp_dsc_bits_per_pixel_read(struct file *f, char __user *buf,
 
 	for (i = 0; i < MAX_PIPES; i++) {
 		pipe_ctx = &aconnector->dc_link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream &&
+		if (pipe_ctx->stream &&
 		    pipe_ctx->stream->link == aconnector->dc_link)
 			break;
 	}
 
-	if (!pipe_ctx) {
-		kfree(rd_buf);
-		return -ENXIO;
-	}
-
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
 		dsc->funcs->dsc_read_state(dsc, &dsc_state);
@@ -2041,12 +2021,12 @@ static ssize_t dp_dsc_bits_per_pixel_write(struct file *f, const char __user *bu
 
 	for (i = 0; i < MAX_PIPES; i++) {
 		pipe_ctx = &aconnector->dc_link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream &&
+		if (pipe_ctx->stream &&
 		    pipe_ctx->stream->link == aconnector->dc_link)
 			break;
 	}
 
-	if (!pipe_ctx || !pipe_ctx->stream)
+	if (!pipe_ctx->stream)
 		goto done;
 
 	// Get CRTC state
@@ -2120,16 +2100,11 @@ static ssize_t dp_dsc_pic_width_read(struct file *f, char __user *buf,
 
 	for (i = 0; i < MAX_PIPES; i++) {
 		pipe_ctx = &aconnector->dc_link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream &&
+		if (pipe_ctx->stream &&
 		    pipe_ctx->stream->link == aconnector->dc_link)
 			break;
 	}
 
-	if (!pipe_ctx) {
-		kfree(rd_buf);
-		return -ENXIO;
-	}
-
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
 		dsc->funcs->dsc_read_state(dsc, &dsc_state);
@@ -2181,16 +2156,11 @@ static ssize_t dp_dsc_pic_height_read(struct file *f, char __user *buf,
 
 	for (i = 0; i < MAX_PIPES; i++) {
 		pipe_ctx = &aconnector->dc_link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream &&
+		if (pipe_ctx->stream &&
 		    pipe_ctx->stream->link == aconnector->dc_link)
 			break;
 	}
 
-	if (!pipe_ctx) {
-		kfree(rd_buf);
-		return -ENXIO;
-	}
-
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
 		dsc->funcs->dsc_read_state(dsc, &dsc_state);
@@ -2257,16 +2227,11 @@ static ssize_t dp_dsc_chunk_size_read(struct file *f, char __user *buf,
 
 	for (i = 0; i < MAX_PIPES; i++) {
 		pipe_ctx = &aconnector->dc_link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream &&
+		if (pipe_ctx->stream &&
 		    pipe_ctx->stream->link == aconnector->dc_link)
 			break;
 	}
 
-	if (!pipe_ctx) {
-		kfree(rd_buf);
-		return -ENXIO;
-	}
-
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
 		dsc->funcs->dsc_read_state(dsc, &dsc_state);
@@ -2333,16 +2298,11 @@ static ssize_t dp_dsc_slice_bpg_offset_read(struct file *f, char __user *buf,
 
 	for (i = 0; i < MAX_PIPES; i++) {
 		pipe_ctx = &aconnector->dc_link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream &&
+		if (pipe_ctx->stream &&
 		    pipe_ctx->stream->link == aconnector->dc_link)
 			break;
 	}
 
-	if (!pipe_ctx) {
-		kfree(rd_buf);
-		return -ENXIO;
-	}
-
 	dsc = pipe_ctx->stream_res.dsc;
 	if (dsc)
 		dsc->funcs->dsc_read_state(dsc, &dsc_state);
-- 
2.25.1



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