Re: [PATCH v5 06/16] drm/vkms: Use const for input pointers in pixel_read an pixel_write functions

Maíra Canal <mcanal@xxxxxxxxxx> · Mon, 25 Mar 2024 11:00:12 -0300

On 3/13/24 14:45, Louis Chauvet wrote:
As the pixel_read and pixel_write function should never modify the input
buffer, mark those pointers const.

Signed-off-by: Louis Chauvet <louis.chauvet@xxxxxxxxxxx>

Reviewed-by: Maíra Canal <mcanal@xxxxxxxxxx>

Best Regards,
- Maíra

---
  drivers/gpu/drm/vkms/vkms_drv.h     |  4 ++--
  drivers/gpu/drm/vkms/vkms_formats.c | 24 ++++++++++++------------
  2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 4bfc62d26f08..3ead8b39af4a 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -61,7 +61,7 @@ struct line_buffer {
   * @out_pixel: destination address to write the pixel
   * @in_pixel: pixel to write
   */
-typedef void (*pixel_write_t)(u8 *out_pixel, struct pixel_argb_u16 *in_pixel);
+typedef void (*pixel_write_t)(u8 *out_pixel, const struct pixel_argb_u16 *in_pixel);
  
  struct vkms_writeback_job {
  	struct iosys_map data[DRM_FORMAT_MAX_PLANES];
@@ -76,7 +76,7 @@ struct vkms_writeback_job {
   * @in_pixel: Pointer to the pixel to read
   * @out_pixel: Pointer to write the converted pixel
   */
-typedef void (*pixel_read_t)(u8 *in_pixel, struct pixel_argb_u16 *out_pixel);
+typedef void (*pixel_read_t)(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel);
  
  /**
   * vkms_plane_state - Driver specific plane state
diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
index b57d85b8b935..b2f8dfc26c35 100644
--- a/drivers/gpu/drm/vkms/vkms_formats.c
+++ b/drivers/gpu/drm/vkms/vkms_formats.c
@@ -76,7 +76,7 @@ static int get_x_position(const struct vkms_frame_info *frame_info, int limit, i
   * They are used in the `vkms_compose_row` function to handle multiple formats.
   */
  
-static void ARGB8888_to_argb_u16(u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
+static void ARGB8888_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
  {
  	/*
  	 * The 257 is the "conversion ratio". This number is obtained by the
@@ -90,7 +90,7 @@ static void ARGB8888_to_argb_u16(u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
  	out_pixel->b = (u16)in_pixel[0] * 257;
  }
  
-static void XRGB8888_to_argb_u16(u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
+static void XRGB8888_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
  {
  	out_pixel->a = (u16)0xffff;
  	out_pixel->r = (u16)in_pixel[2] * 257;
@@ -98,7 +98,7 @@ static void XRGB8888_to_argb_u16(u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
  	out_pixel->b = (u16)in_pixel[0] * 257;
  }
  
-static void ARGB16161616_to_argb_u16(u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
+static void ARGB16161616_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
  {
  	u16 *pixel = (u16 *)in_pixel;
  
@@ -108,7 +108,7 @@ static void ARGB16161616_to_argb_u16(u8 *in_pixel, struct pixel_argb_u16 *out_pi
  	out_pixel->b = le16_to_cpu(pixel[0]);
  }
  
-static void XRGB16161616_to_argb_u16(u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
+static void XRGB16161616_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
  {
  	u16 *pixel = (u16 *)in_pixel;
  
@@ -118,7 +118,7 @@ static void XRGB16161616_to_argb_u16(u8 *in_pixel, struct pixel_argb_u16 *out_pi
  	out_pixel->b = le16_to_cpu(pixel[0]);
  }
  
-static void RGB565_to_argb_u16(u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
+static void RGB565_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
  {
  	u16 *pixel = (u16 *)in_pixel;
  
@@ -143,7 +143,7 @@ static void RGB565_to_argb_u16(u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
   * It is used to avoid null pointer to be used as a function. In theory, this function should
   * never be called, except if you found a bug in the driver/DRM core.
   */
-static void black_to_argb_u16(u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
+static void black_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
  {
  	out_pixel->a = (u16)0xFFFF;
  	out_pixel->r = 0;
@@ -189,7 +189,7 @@ void vkms_compose_row(struct line_buffer *stage_buffer, struct vkms_plane_state
   * They are used in the `vkms_writeback_row` to convert and store a pixel from the src_buffer to
   * the writeback buffer.
   */
-static void argb_u16_to_ARGB8888(u8 *out_pixel, struct pixel_argb_u16 *in_pixel)
+static void argb_u16_to_ARGB8888(u8 *out_pixel, const struct pixel_argb_u16 *in_pixel)
  {
  	/*
  	 * This sequence below is important because the format's byte order is
@@ -207,7 +207,7 @@ static void argb_u16_to_ARGB8888(u8 *out_pixel, struct pixel_argb_u16 *in_pixel)
  	out_pixel[0] = DIV_ROUND_CLOSEST(in_pixel->b, 257);
  }
  
-static void argb_u16_to_XRGB8888(u8 *out_pixel, struct pixel_argb_u16 *in_pixel)
+static void argb_u16_to_XRGB8888(u8 *out_pixel, const struct pixel_argb_u16 *in_pixel)
  {
  	out_pixel[3] = 0xff;
  	out_pixel[2] = DIV_ROUND_CLOSEST(in_pixel->r, 257);
@@ -215,7 +215,7 @@ static void argb_u16_to_XRGB8888(u8 *out_pixel, struct pixel_argb_u16 *in_pixel)
  	out_pixel[0] = DIV_ROUND_CLOSEST(in_pixel->b, 257);
  }
  
-static void argb_u16_to_ARGB16161616(u8 *out_pixel, struct pixel_argb_u16 *in_pixel)
+static void argb_u16_to_ARGB16161616(u8 *out_pixel, const struct pixel_argb_u16 *in_pixel)
  {
  	u16 *pixel = (u16 *)out_pixel;
  
@@ -225,7 +225,7 @@ static void argb_u16_to_ARGB16161616(u8 *out_pixel, struct pixel_argb_u16 *in_pi
  	pixel[0] = cpu_to_le16(in_pixel->b);
  }
  
-static void argb_u16_to_XRGB16161616(u8 *out_pixel, struct pixel_argb_u16 *in_pixel)
+static void argb_u16_to_XRGB16161616(u8 *out_pixel, const struct pixel_argb_u16 *in_pixel)
  {
  	u16 *pixel = (u16 *)out_pixel;
  
@@ -235,7 +235,7 @@ static void argb_u16_to_XRGB16161616(u8 *out_pixel, struct pixel_argb_u16 *in_pi
  	pixel[0] = cpu_to_le16(in_pixel->b);
  }
  
-static void argb_u16_to_RGB565(u8 *out_pixel, struct pixel_argb_u16 *in_pixel)
+static void argb_u16_to_RGB565(u8 *out_pixel, const struct pixel_argb_u16 *in_pixel)
  {
  	u16 *pixel = (u16 *)out_pixel;
  
@@ -260,7 +260,7 @@ static void argb_u16_to_RGB565(u8 *out_pixel, struct pixel_argb_u16 *in_pixel)
   * It is used to avoid null pointer to be used as a function. In theory, this should never
   * happen, except if there is a bug in the driver
   */
-static void argb_u16_to_nothing(u8 *out_pixel, struct pixel_argb_u16 *in_pixel)
+static void argb_u16_to_nothing(u8 *out_pixel, const struct pixel_argb_u16 *in_pixel)
  {}
  
  /**







