Re: [Linux-fbdev-devel] geodefb issues, possible patch

[David V. <dv...@ar...>]

Jorge Luis Zapata Muga wrote:
> 
> i am having problems with the geode fb driver in 2.6 kernels. it seems
> that it cant ioremap the video registers. ive debug a little bit of
> code and compared it to the
> previous kernel tree (2.4) geode fb driver amd (i think) provided. the
> old driver works perfectly on my SBP.

What CPU and companion chip is on this board?  The current 2.6 driver
only supports the Geode GX1 with CS5530A.

What kernel version are you using?

> ok here are the things i found:
> * when requesting the pci regions all the pci_resource_start,
> pci_resource_len return 0's

Can you send the output of 'lspci -vvv -x' for the companion chip video
device?

> * the hardcoded offsets for mapping are different from what i found in
> the other driver, ive changed them to the older values. (to map the
> video reg, display controller reg, and the fb memory)

Er. I doubt this is the correct thing to do since the driver matches the
GX1 data sheet.

> * the display controller functions to blank the screen, configure
> display, set clock freq, etc used the vid_regs  for writel readl
> instead (as seen in the other driver) of the dc_vid (display
> controller registers).

I don't follow you here. The display controller has nothing to do with
the DCLK frequency nor blanking the screen -- that's purely a function
of the video device in the companion chip.

> i have a patch if someone is interested. the problem is that i dont
> know what else to do, as i cant debug (with printf's) the driver as i
> dont have a screen, how does a fb driver gets debugged?

I use a serial console.

> does this driver actually works?

It works on the board I have.

> maybe i have an issue with the pci detection?

It's possible that the BIOS not correctly initializing all PCI devices
correctly.  I don't really know a whole lot about PCI on x86 platforms,
though.

David Vrabel

ps. I'd suggest ignoring the old 2.4 driver for the most part since it's
crap and very hard to follow -- refer to the datasheets instead.
-- 
David Vrabel, Design Engineer

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