Tried mesa-18.2.0_rc2 but still no luck.

$ glxinfo | grep -i opengl
r300: DRM version: 2.50.0, Name: ATI R350, ID: 0x4e48, GB: 2, Z: 1
r300: GART size: 253 MB, VRAM size: 256 MB
r300: AA compression RAM: YES, Z compression RAM: YES, HiZ RAM: YES
OpenGL vendor string: X.Org R300 Project
OpenGL renderer string: ATI R350
OpenGL version string: 2.1 Mesa 18.2.0-rc2
OpenGL shading language version string: 1.20
OpenGL extensions:
r300: DRM version: 2.50.0, Name: ATI R350, ID: 0x4e48, GB: 2, Z: 1
r300: GART size: 253 MB, VRAM size: 256 MB
r300: AA compression RAM: YES, Z compression RAM: YES, HiZ RAM: YES
OpenGL ES profile version string: OpenGL ES 2.0 Mesa 18.2.0-rc2
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 1.0.16
OpenGL ES profile extensions: