drm timing problems in sama5d3 Xplained.

[Boris Brezillon]

Hi Alex,

On Mon, 5 Sep 2016 11:04:51 +0200
Alex Vazquez  wrote:

> Hi All.
> I am using DRM in a sama5d3 Xplained with display TM43 and I've found with
> the following problem:
> I deleted the network interfaces in the device tree for my system to boot
> faster. My problem is that now the startup script run before the driver has
> loaded correctly.
> I explain better:
> The startup script begin to appear before the creation of the framebuffer
> message appears. (See LogKernel.txt)
> 
> atmel-hlcdc-display-controller atmel-hlcdc-dc: fb0:  frame buffer device
> 
> 
> 1 - I can't use the framebuffer until the message is not displayed. (This
> did not matter. I want to use drm.)
> 2 - DRM don't work fine. If I try to paint on the screen (using planes)
> before the message it is created framebuffer appears, nothing appears on
> the display.
> 
> This problem I can replicate with the demo atmel if I remove network
> interfaces in the device tree and adding a startup script that uses drm.
> 
> I add the demo with the modified device tree so you can prove that occurs.
> 
> https://drive.google.com/file/d/0B3EMwEbIHhkAbDhGMU1BcEVoYkU/view?usp=sharing
> 
> You only need to add the startup script in /etc/rcS.d/
> 
> #!/bin/sh
> > modetest -M atmel-hlcdc -P 26:480x272+0+0 at AR15  
> 
> 
> I also tested with the latest version of kernel 4.8 RC3 and the problem is
> still happening.

It seems that the atmel-hlcdc DRM device probe is deferred because some
elements in the display pipeline are missing (the display itself, the
backlight attached to the display, or even the PWM attached to the
backlight).

Can you check if the /dev/dri/xxx files are present when you reach your
init script?

If that's not the case, can you make sure you compiled the different
drivers needed for the display pipeline to work correctly statically?

Thanks,

Boris

drm timing problems in sama5d3 Xplained.

[Alex Vazquez]

Hi All.
I am using DRM in a sama5d3 Xplained with display TM43 and I've found with
the following problem:
I deleted the network interfaces in the device tree for my system to boot
faster. My problem is that now the startup script run before the driver has
loaded correctly.
I explain better:
The startup script begin to appear before the creation of the framebuffer
message appears. (See LogKernel.txt)

atmel-hlcdc-display-controller atmel-hlcdc-dc: fb0:  frame buffer device


1 - I can't use the framebuffer until the message is not displayed. (This
did not matter. I want to use drm.)
2 - DRM don't work fine. If I try to paint on the screen (using planes)
before the message it is created framebuffer appears, nothing appears on
the display.

This problem I can replicate with the demo atmel if I remove network
interfaces in the device tree and adding a startup script that uses drm.

I add the demo with the modified device tree so you can prove that occurs.

https://drive.google.com/file/d/0B3EMwEbIHhkAbDhGMU1BcEVoYkU/view?usp=sharing

You only need to add the startup script in /etc/rcS.d/

#!/bin/sh
> modetest -M atmel-hlcdc -P 26:480x272+0+0 at AR15


I also tested with the latest version of kernel 4.8 RC3 and the problem is
still happening.

Thanks!
Regards!
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-- next part --
[0.00] Booting Linux on physical CPU 0x0
[0.00] Linux version 4.1.0-linux4sam_5.3 (ldesroches at ibiza) (gcc 
version 5.2.0 (GCC) ) #1 Sat Apr 16 13:00:00 CEST 2016
[0.00] CPU: ARMv7 Processor [410fc051] revision 1 (ARMv7), cr=10c53c7d
[0.00] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing 
instruction cache
[0.00] Machine model: Atmel SAMA5D3 Xplained TM43xx
[0.00] cma: Reserved 64 MiB at 0x2800
[0.00] Memory policy: Data cache writeback
[0.00] On node 0 totalpages: 65536
[0.00] free_area_init_node: node 0, pgdat c06e20c4, node_mem_map 
cfdda000
[0.00]   Normal zone: 512 pages used for memmap
[0.00]   Normal zone: 0 pages reserved
[0.00]   Normal zone: 65536 pages, LIFO batch:15
[0.00] CPU: All CPU(s) started in SVC mode.
[0.00] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
[0.00] pcpu-alloc: [0] 0 
[0.00] Built 1 zonelists in Zone order, mobility grouping off.  Total 
pages: 65024
[0.00] Kernel command line: console=ttyS0,115200 
mtdparts=atmel_nand:256k(bootstrap)ro,512k(uboot)ro,256k(env),256k(env_redundant),256k(spare),512k(dtb),6M(kernel)ro,-(ro6
[0.00] PID hash table entries: 1024 (order: 0, 4096 bytes)
[0.00] Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)
[0.00] Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
[0.00] Memory: 186824K/262144K available (4985K kernel code, 179K 
rwdata, 1660K rodata, 192K init, 159K bss, 9784K reserved, 65536K cma-reserved)
[0.00] Virtual kernel memory layout:
   vector  : 0x - 0x1000   (   4 kB)
   fixmap  : 0xffc0 - 0xfff0   (3072 kB)
   vmalloc : 0xd080 - 0xff00   ( 744 MB)
   lowmem  : 0xc000 - 0xd000   ( 256 MB)
   modules : 0xbf00 - 0xc000   (  16 MB)
 .text : 0xc0008000 - 0xc0685928   (6647 kB)
 .init : 0xc0686000 - 0xc06b6000   ( 192 kB)
 .data : 0xc06b6000 - 0xc06e2ed8   ( 180 kB)
  .bss : 0xc06e2ed8 - 0xc070ad3c   ( 160 kB)
[0.00] NR_IRQS:16 nr_irqs:16 16
[0.00] clocksource pit: mask: 0xfff max_cycles: 0xfff, 
max_idle_ns: 14479245754 ns
[0.00] sched_clock: 32 bits at 100 Hz, resolution 1000ns, wraps 
every 2147483647500ns
[0.00] Console: colour dummy device 80x30
[0.05] Calibrating delay loop... 351.43 BogoMIPS (lpj=1757184)
[0.06] pid_max: default: 32768 minimum: 301
[0.06] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[0.06] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[0.06] CPU: Testing write buffer coherency: ok
[0.06] Setting up static identity map for 0x20008200 - 0x20008258
[0.06] devtmpfs: initialized
[0.07] VFP support v0.3: implementor 41 architecture 2 part 30 variant 
5 rev 1
[0.08] clocksource jiffies: mask: 0x max_cycles: 0x, 
max_idle_ns: 1911260446275 ns
[0.08] pinctrl core: initialized pinctrl subsystem
[0.08] NET: Registered protocol family 16
[0.11] DMA: preallocated 256 KiB pool for atomic coherent allocations
[0.11] cpuidle: using governor ladder
[0.11] cpuidle: using governor menu
[0.11] AT91: Detected SoC family: sama5d3
[0.11]