2010-01-11 11:51:10     qt/jpegview framebuffer problem

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2010-01-11 11:51:10     qt/jpegview framebuffer problem

Mark Urup (DENMARK)

Message: 84416   

 

Hi,

 

I can't seem to display any of the example/demo programs with qt (or my own). I know the qt program runs because it prints to the console. It just gives me a blank screen. (or the last thing that was displayed (so the last thing in the framebuffer)).

The problem is the same if I use qt 4.2 which worked on 2008R1.

 

The qws framebuffer program from QT works just fine, and displays the three squares it supposed to.

 

Whats even more stange is that I can run the video_test program, and see the test output, but I can't use jpegview to see jpg images. Again, blank screen (or latest framebuffer output).

 

Im using SVN source code (2010-pre-sv).

 

It's a custom board, and a custom display driver, but it worked in 2008R1 and with qt 4.2.

I needeed to update because of a deadlock issue i the serial port.

 

I need QT to work (either the old qt 4.2 or preferbly the new 4.5), so does QT have some "undocumented" dependencies in the kernel, or userspace?

 

Oh, and ts_calibrate also works just fine...

 

 

 

Any idea's as to where the problem might be?

 

I've attached my configuration files, if it helps.

 

config-user

config-kernel

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2010-01-11 11:59:44     Re: qt/jpegview framebuffer problem

Mike Frysinger (UNITED STATES)

Message: 84417   

 

jpegview is a very simple program.  i would start your debugging with that if it isnt even working.

 

might want topost your display driver code too.

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2010-01-11 22:17:33     Re: qt/jpegview framebuffer problem

Sonic Zhang (CHINA)

Message: 84430   

 

Please use built QT and application into FDPIC mode. In FLAT mode, QT jpeg plugin is disabled in all available releases. It is fixed recently in SVN trunk by build QT plugin into static linked library.

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2010-01-12 04:37:49     Re: qt/jpegview framebuffer problem

Mark Urup (DENMARK)

Message: 84454   

 

I'm building it as FDPIC, and I'm simply trying to show ANYTHING on the display (button/label, whatever).

 

I just thought it was strange that jpegview didn't work as well.

 

I'll take a look at jpegview today and see if I can find some common issue; Can anybody confirm that the framebuffer/qt subsystem is working properly in svn?

 

 

 

I've also attached our display driver (note: it uses a gpio on the ad7877 on switch the blacklight on and off)

 

bf537-nec-ln6448bc20-18d.c

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2010-01-12 09:36:10     Re: qt/jpegview framebuffer problem

Mark Urup (DENMARK)

Message: 84467   

 

I've found the error (I think), at least for jpegview.

 

 

 

If I change line 380 in mian.c of jpegview, from:

 

        framebase = mmap(0, initial_vi.smem_len, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);

 

to

 

        framebase = mmap(0, initial_vi.smem_len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);

 

it works, and I can get images displayed on the screen.

 

However, this application works just fine under uclinux 2008, so what has changed, and where/what do I need to change to make qt work?

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2010-01-12 09:48:37     Re: qt/jpegview framebuffer problem

Michael Hennerich (GERMANY)

Message: 84469    >However, this application works just fine under uclinux 2008, so what

>has changed, and where/what do I need to change to make qt work?

 

We implemented get_fb_unmapped_area() - thus we don't longer need to use the MAP_PRIVATE cheat.

The new nommu mmap code actually prevents MAP_PRIVATE to further work.

 

I'll take a look and revert the modified apps.

 

-Michael

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2010-01-12 10:02:41     Re: qt/jpegview framebuffer problem

Michael Hennerich (GERMANY)

Message: 84471    Just checked qt lib suffers the same problem.

Please revert and delete the qt-4.5.0-nommu-mmap.patch

And build again.

 

-Michael

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2010-01-13 04:35:27     Re: qt/jpegview framebuffer problem

Mark Urup (DENMARK)

Message: 84528   

 

Perfect.

 

That fixes the issue.

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2010-01-13 04:43:14     Re: qt/jpegview framebuffer problem

Michael Hennerich (GERMANY)

Message: 84529    Take a look here:

Removing only the first patch from the nommu-mmap patch is sufficient.

 

  blackfin.uclinux.org/gf/project/uclinux-dist/forum/?_forum_action=MessageReply&action=ForumBrowse&message_id=84504

 

-Michael

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