Revert "ARM: socfpga: Remove socfpga_sdram_apply_static_cfg()

[Wolfgang Grandegger]

Am 06.08.20 um 13:04 schrieb Marek Vasut:
> On 8/6/20 12:53 PM, Wolfgang Grandegger wrote:
>> This reverts commit c5f4b805755912a3d2fe20f014b6b6ab0473bd73.
>>
>> Conflicts:
>> 	arch/arm/mach-socfpga/misc_gen5.c
>>
>> Without socfpga_sdram_apply_static_cfg(), the system hangs when Linux
>> calls altvipfb2_start_hw() of the Intel Video and Image Processing(VIP)
>> Frame Buffer II driver (drivers/video/fbdev/altvipfb2.c)
> 
> There is no such driver in mainline U-Boot or Linux.

It's a simple frame buffer driver from linux-socfpga for the IP core
Intel Video and Image Processing(VIP) Frame Buffer II. It actually
hangs here when the streaming starts:

https://github.com/altera-opensource/linux-socfpga/blob/socfpga-5.4.44-lts/drivers/video/fbdev/altvipfb2.c#L69

I can also hang the system if I setup and start the FB with just a
few U-Boot commands. I think the system hangs when the IP core starts
reading the FB data from the system memory.

>> , but only
>> after a power cycle (cold boot). The issue does not show up after a
>> soft reset (warm boot) and with v2018.11.
> 
> See the commit message of the patch this is reverting, I believe there
> is a deeper issue with the static config register. Can you investigate?

I read the commit message, but well, I can't follow all the details :(.
On the other hand, it seems also not clear why the fix was added. Any
idea what to investigate.

Wolfgang