Dear Maintainers,
I am writing to seek clarification regarding the implementation of the
drm_draw_fill24 function in the DRM subsystem. Specifically, Coverity has
flagged (CID 1602416) the issue in the following line in drm/drm_draw.c
--> iosys_map_wr(dmap, off + 2, u8, (color & 0x00FF0000) >> 16);
I have some questions about handling of the color parameter in the function.
The function currently accepts a u16 value as the color parameter and uses
bitwise operations to extract the RGB components. However, the mask 0x00FF0000
refers to bits 16–23, which are always zero for a u16 value. Therefore, the
expression (color & 0x00FF0000) will always result in 0.
Could you please confirm:
1. Is the truncation of 32-bit color value to 16 bits the intended behavior?
2. Alternatively, should the function be updated to accept 32-bit values
as input as the function is called with 32 bit values elsewhere?
Thank you for your time. Please let me know if further information or context
is required.
-Dheeraj
