On 21/11/2019 12:21 pm, Christian Zigotzky wrote:

On 21 November 2019 at 01:16 pm, Christian Zigotzky wrote:

quoted

On 21 November 2019 at 08:29 am, Christoph Hellwig wrote:

quoted

On Sat, Nov 16, 2019 at 08:06:05AM +0100, Christian Zigotzky wrote:

quoted

/*
  *  DMA addressing mode.
  *
  *  0 : 32 bit addressing for all chips.
  *  1 : 40 bit addressing when supported by chip.
  *  2 : 64 bit addressing when supported by chip,
  *      limited to 16 segments of 4 GB -> 64 GB max.
  */
#define   SYM_CONF_DMA_ADDRESSING_MODE 
CONFIG_SCSI_SYM53C8XX_DMA_ADDRESSING_MODE

Cyrus config:

CONFIG_SCSI_SYM53C8XX_DMA_ADDRESSING_MODE=1

I will configure “0 : 32 bit addressing for all chips” for the RC8. 
Maybe this is the solution.

0 means you are going to do bounce buffering a lot, which seems
generally like a bad idea.

But why are we talking about the sym53c8xx driver now?  The last issue
you reported was about video4linux allocations.

Both drivers have the same problem. They don't work if we have more 
than 3.5GB RAM. I try to find a solution until you have a good 
solution. I have already a solution for V4L but I still need one for 
the sym53c8xx driver.

OK, you mean that "0" is a bad idea but maybe it works until you have a 
solution. ;-)

Is this on the same machine with the funny non-power-of-two bus_dma_mask 
as your other report? If so, does Nicolas' latest patch[1] help at all?

Robin.

[1] 
https://lore.kernel.org/linux-iommu/20191121092646.8449-1-nsaenzjulienne@suse.de/T/#u (local)