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Kernel 3.17 locks up when using display VDMA

Question asked by milosoftware on Nov 12, 2014
Latest reply on Nov 24, 2014 by larsc

I merged the 3.17 kernel from the ADI tree, the "xcomm_zynq_new_pcore_regmap" branch which I've been using for quite a while.

 

After installing this new kernel, I cannot use the VMDA based framebuffers for actually running applications on it.

 

After loading the kernel modules the framebuffer appears to operate fine. This is the case for the ADI HDMI (reference design) as well as a custom LVDS display that uses similar VMDA code.

 

If I do something like "cat /dev/urandom > /dev/fb0" I get a nice noise display on the monitor or panel.

 

If I start any application that maps the display, like the touchscreen calibration utility (ts_calibrate) or a QT application, the system locks up. The console no longer accepts input, and starts complaining about missing interrupts and such.

 

Everything else works fine on the new kernel.

 

Are you aware of any change in the VMDA code or logic that might explain this behaviour?

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