yan chengzhi

a 6x4 matrix in framebuffer is modified by others

Discussion created by yan chengzhi on Aug 22, 2009
Latest reply on Aug 28, 2009 by Tom Thompson

   I am using the ltib-nommu-20081218 version of BSP for MCF5329,with a 480x272 LCD panel .But there is a black rectangle at the coordinate (0,84), 4 pixel width and 6 pixel heigh.I just used two method to write the framebuffer.One method is open /dev/fbo,lseek,then write 0xffffffff ,after all buffer is wrote,then read the buffer and print readed data,in the rectangle the is 0.After write 0xffffffff,the code read the same address,the data is still 0xffffffff.But when all buffers is wrote,the data in the rectangle is modified.Another method is using mmap,it is the same.

  I tried to modified the linux/drivers/video/mcf-fb.c file cutting off all hardware related code.It is the same conclusion.

  Anyone who met the problem tell me how to resolve it.