linux-kernel - [PATCH v2 1/5] drm/solomon: Move calls to drm_gem_fb_end

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Message-Id: <20250920-improve-ssd130x-v2-1-77721e87ae08@gmail.com>
Date: Sat, 20 Sep 2025 11:45:41 +0200
From: Iker Pedrosa <ikerpedrosam@...il.com>
To: Javier Martinez Canillas <javierm@...hat.com>, 
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>, 
 David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>
Cc: dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org, 
 Iker Pedrosa <ikerpedrosam@...il.com>
Subject: [PATCH v2 1/5] drm/solomon: Move calls to drm_gem_fb_end_cpu*()

Calls to drm_gem_fb_end_cpu*() should be between the calls to
drm_dev*(), and not hidden inside some other function. This way the
critical section code is visible at a glance, keeping it short and
improving maintainability.

Reviewed-by: Javier Martinez Canillas <javierm@...hat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@...e.de>
Signed-off-by: Iker Pedrosa <ikerpedrosam@...il.com>
---
 drivers/gpu/drm/solomon/ssd130x.c | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c
index dd2006d51c7a2fc8501904565da806aa47333ad6..d98015d6d28505d028ee958831e3cefdb8a9c397 100644
--- a/drivers/gpu/drm/solomon/ssd130x.c
+++ b/drivers/gpu/drm/solomon/ssd130x.c
@@ -1016,15 +1016,9 @@ static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb,
 
 	dst_pitch = DIV_ROUND_UP(drm_rect_width(rect), 8);
 
-	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
-	if (ret)
-		return ret;
-
 	iosys_map_set_vaddr(&dst, buf);
 	drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, vmap, fb, rect, fmtcnv_state);
 
-	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
-
 	ssd130x_update_rect(ssd130x, rect, buf, data_array);
 
 	return ret;
@@ -1048,15 +1042,9 @@ static int ssd132x_fb_blit_rect(struct drm_framebuffer *fb,
 
 	dst_pitch = drm_rect_width(rect);
 
-	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
-	if (ret)
-		return ret;
-
 	iosys_map_set_vaddr(&dst, buf);
 	drm_fb_xrgb8888_to_gray8(&dst, &dst_pitch, vmap, fb, rect, fmtcnv_state);
 
-	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
-
 	ssd132x_update_rect(ssd130x, rect, buf, data_array);
 
 	return ret;
@@ -1078,15 +1066,9 @@ static int ssd133x_fb_blit_rect(struct drm_framebuffer *fb,
 
 	dst_pitch = drm_format_info_min_pitch(fi, 0, drm_rect_width(rect));
 
-	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
-	if (ret)
-		return ret;
-
 	iosys_map_set_vaddr(&dst, data_array);
 	drm_fb_xrgb8888_to_rgb332(&dst, &dst_pitch, vmap, fb, rect, fmtcnv_state);
 
-	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
-
 	ssd133x_update_rect(ssd130x, rect, data_array, dst_pitch);
 
 	return ret;
@@ -1232,6 +1214,9 @@ static void ssd130x_primary_plane_atomic_update(struct drm_plane *plane,
 	if (!drm_dev_enter(drm, &idx))
 		return;
 
+	if (drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE))
+		goto out_drm_dev_exit;
+
 	drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
 	drm_atomic_for_each_plane_damage(&iter, &damage) {
 		dst_clip = plane_state->dst;
@@ -1245,6 +1230,9 @@ static void ssd130x_primary_plane_atomic_update(struct drm_plane *plane,
 				     &shadow_plane_state->fmtcnv_state);
 	}
 
+	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
+
+out_drm_dev_exit:
 	drm_dev_exit(idx);
 }
 
@@ -1267,6 +1255,9 @@ static void ssd132x_primary_plane_atomic_update(struct drm_plane *plane,
 	if (!drm_dev_enter(drm, &idx))
 		return;
 
+	if (drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE))
+		goto out_drm_dev_exit;
+
 	drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
 	drm_atomic_for_each_plane_damage(&iter, &damage) {
 		dst_clip = plane_state->dst;
@@ -1280,6 +1271,9 @@ static void ssd132x_primary_plane_atomic_update(struct drm_plane *plane,
 				     &shadow_plane_state->fmtcnv_state);
 	}
 
+	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
+
+out_drm_dev_exit:
 	drm_dev_exit(idx);
 }
 
@@ -1301,6 +1295,9 @@ static void ssd133x_primary_plane_atomic_update(struct drm_plane *plane,
 	if (!drm_dev_enter(drm, &idx))
 		return;
 
+	if (drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE))
+		goto out_drm_dev_exit;
+
 	drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
 	drm_atomic_for_each_plane_damage(&iter, &damage) {
 		dst_clip = plane_state->dst;
@@ -1313,6 +1310,9 @@ static void ssd133x_primary_plane_atomic_update(struct drm_plane *plane,
 				     &shadow_plane_state->fmtcnv_state);
 	}
 
+	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
+
+out_drm_dev_exit:
 	drm_dev_exit(idx);
 }
 

-- 
2.51.0