nanogui: Thread: Mouse problems

Hi All,

I am using microwindows win32 API for developing a small GUI app to run
on linux for an embedded system. The system is based on x86 single board
computer with 32MB of flash memory and 128MB SDRAM. The app uses
framebuffer over a vesa compliant card and gpm mouse support with a ps2
mouse.

When I run the app from an uncompressed file system on a test HDD
instead of flash, the app runs fine. When I try to use ramdisk or tmpfs
for storing a part of fs (/usr/local directory), the mouse response
becomes very bad. Mouse seems to move very slowly and the cursor blinks
rapidly. The refresh on screen seems to have been badly affected.
Another observation is the characters typed on keyboard take time to
appear on the screen.

What could be the problem?

: When I run the app from an uncompressed file system on a test HDD
: instead of flash, the app runs fine. When I try to use ramdisk or tmpfs
: for storing a part of fs (/usr/local directory), the mouse response
: becomes very bad. Mouse seems to move very slowly and the cursor blinks
: rapidly. The refresh on screen seems to have been badly affected.
: Another observation is the characters typed on keyboard take time to
: appear on the screen.

It almost seems like the system may be polling, rather than waiting
for an event.  Are you running the same kernel?  Perhaps the system
you've built for ramdisk is failing during the select() call, and polling
as a result.  I suggest putting a printf() in the mouse driver read routine,
to check whether the application is really waiting for an event, or polling
constantly.  The cursor blink is because Microwindows uses a soft
cursor and must hide the cursor on every mouse move, which can 
cause a blink if it happens too rapidly.  Hope this helps!

Regards,

Greg

> : When I run the app from an uncompressed file system on a test HDD
> : instead of flash, the app runs fine. When I try to use ramdisk or tmpfs
> : for storing a part of fs (/usr/local directory), the mouse response
> : becomes very bad. Mouse seems to move very slowly and the cursor blinks
> : rapidly. The refresh on screen seems to have been badly affected.
> : Another observation is the characters typed on keyboard take time to
> : appear on the screen.
> 
> It almost seems like the system may be polling, rather than waiting
> for an event.  Are you running the same kernel?  Perhaps the system
> you've built for ramdisk is failing during the select() call, and polling
> as a result.  I suggest putting a printf() in the mouse driver read routine,
> to check whether the application is really waiting for an event, or polling
> constantly.  The cursor blink is because Microwindows uses a soft
> cursor and must hide the cursor on every mouse move, which can
> cause a blink if it happens too rapidly.  Hope this helps!

I am using the same kernel and rest of the files. I just moved
/usr/local from HDD to memory (I made a tarball of /usr/local/, I mount
a tmpfs volume at /usr/local and uncompress the above tarball there). I
tried putting a printf() just before return in the mouse driver read
routine in mou_gpm.c but this printf() never appears on the terminal o/p
of the application.

BTW, could this be a framebuffer refresh issue?

Regards
Sunil