Re: [Xenomai-core] xenomai and framebuffer-ipu on target iMx35

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

François Beaufort wrote:
> Hello,
> 
> I have to port Linux-xenomai on target Phytec PhyCARD-M iMx35 (ARM 11 core) and I need your help.
> 
> I reconfigured the kernel from the configuration provided by Phytec :
> 
>     - CONFIG_PREEMPT = y
>     - CONFIG_VGA_CONSOLE = n
>     - CONFIG_MX3_IPU = n
>     - CONFIG_FB_MX3 = n
>     - CONFIG_USB_ISP1760 = n
> 
> So, Linux-xenomai runs on the target, but I can't have pictures on the display (the configuration of the framebuffer is not set : CONFIG_MX3_IPU and CONFIG_FB_MX3).
> 
> I would like to enable xenomai and the framebuffer.
> 
> When I patch Linux with adeos-ipipe, disable xenomai and enable ipu (image processing unit), the kernel doesn't start :
> 
>         booting kernel of type uimage from /dev/ram0.kernel
>            Verifying Checksum ... OK
>            Image Name:   Linux-2.6.35.9
>            Created:      2011-04-20   7:14:44 UTC
>            Image Type:   ARM Linux Kernel Image (uncompressed)
>            Data Size:    2446512 Bytes =  2.3 MB
>            Load Address: 80008000
>            Entry Point:  80008000
>         OK
>         commandline: console=ttymxc0,115200 video=mx3fb:Primeview-PD050VL1 ip=192.168.0.195::192.168.0.1:255.255.255.0::: root=/dev/nfs   nfsroot=192.168.0.84:/opt/francois/nfs_imx35_xenom;
>         arch_number: 2595
> 
>         Starting kernel ...
> 
>         Linux version 2.6.35.9 (francois@domain.hid) (gcc version 4.3.2 (OSELAS.Toolchain-1.99.3) ) #2 PREEMPT Wed Apr 20 09:14:32 CEST 2011
>         CPU: ARMv6-compatible processor [4117b363] revision 3 (ARMv6TEJ), cr=00c5387f
>         CPU: VIPT nonaliasing data cache, VIPT nonaliasing instruction c
> 
> 
> I think there is a conflict between ipipe and ipu but I don't know why.
> 
> IPU depends on dma engine.
> 
> When I read the /proc files, I can't see IRQ conflicts nor memory conflicts.
> 
> The ipu driver consists of two C files : ipu_idmac.c and ipu_irq.c. 
> When I disable ipu_idma.c, I have 4 more IRQs (CONFIG_MX3_IPU_IRQS = 4) and Linux-ipipe (and xenomai) starts but I can't have pictures on the display.
> 
> I can't debug with printk because the printk calls modify the behaviour.

How so?

> 
> Do you have any idea ?

First thing to confirm: does the same configuration which does not work
with I-pipe enabled work with I-pipe disable. I mean, the exact same
configuration except for CONFIG_IPIPE?

Second thing: if the IPU dma engine, whatever, uses an interrupt, can
you compare the counters in /proc/interrupts for this interrupt with and
without CONFIG_IPIPE enabled?


-- 
					    Gilles.