Bug 205201 - overflow of DMA mask and bus mask

[Christian Zigotzky]

Hi All,

We still have DMA problems with some PCI devices. Since the PowerPC 
updates 4.21-1 [1] we need to decrease the RAM to 3500MB (mem=3500M) if 
we want to work with our PCI devices. The FSL P5020 and P5040 have these 
problems currently.

Error message:

[   25.654852] bttv 1000:04:05.0: overflow 0x00000000fe077000+4096 of 
DMA mask ffffffff bus mask df000000

All 5.x Linux kernels can't initialize a SCSI PCI card anymore so 
booting of a Linux userland isn't possible.

PLEASE check the DMA changes in the PowerPC updates 4.21-1 [1]. The 
kernel 4.20 works with all PCI devices without limitation of RAM.

We created a bug report a month ago. [2]

Thanks,
Christian

[1] 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8d6973327ee84c2f40dd9efd8928d4a1186c96e2
[2] https://bugzilla.kernel.org/show_bug.cgi?id=205201