Debugging pxafb and am200epd

Hi Eric,

Just some quick questions and notes while trying to implement am200epd
sharing pxafb's framebuffer.

1. pxafb_init is set to __devinit, but it is only called from
module_init. Is my understanding correct that it should be __init?
2. pxafb currently doesn't implement module unloading support.  Is
there a reason for this?

3. I'm seeing weird behavior with insmod of am200epd on my test system
on a gumstix. Probably something that I'm doing wrong but I wanted to
ask advice here anyway. Here's what I'm doing:
# insmod drivers/video/cfbcopyarea.ko && insmod
drivers/video/cfbfillrect.ko && insmod drivers/video/cfbimgblt.ko
# insmod drivers/video/syscopyarea.ko && insmod
drivers/video/sysfillrect.ko && insmod drivers/video/sysimgblt.ko &&
insmod drivers/video/fb_sys_fops.ko
# insmod drivers/video/metronomefb.ko ; insmod drivers/video/pxafb.ko
# grep pxafb_probe /proc/kallsyms
bf014000 t pxafb_probe  [pxafb]
# grep bf014000 /proc/kallsyms
bf014000 t pxafb_probe  [pxafb]
bf014000 t $a   [pxafb]

The reason I was debugging this was because platform_device_add was
failing from am200epd when am200epd is trying to add pxa2xx-fb. It
would fail from platform_drv_probe. I found that it was because the
pxafb's probe routine somehow gets replaced by other stuff. I was
worried if it was due to am200epd so I then took out all the code from
am200epd's init_module so it does nothing other than return 0. So the
following insmod is of am200epd that has a completely empty
init_module.

# insmod arch/arm/mach-pxa/am200epd.ko

# grep pxafb_probe /proc/kallsyms
bf014000 t pxafb_probe  [pxafb]

# grep bf014000 /proc/kallsyms
bf014000 t am200_exit   [am200epd]
bf014000 t $a   [am200epd]
bf014000 t cleanup_module       [am200epd]
bf014000 t pxafb_probe  [pxafb]
bf014000 t $a   [pxafb]

The above doesn't make sense to me. I don't understand why am200_exit
is overloaded at the same address as pxafb_probe. Any suggestions on
how to debug this?

Thanks,
jaya

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