Re: Bug 205201 - Booting halts if Dawicontrol DC-2976 UW SCSI board installed, unless RAM size limited to 3500M

[Robin Murphy]

On 21/11/2019 12:21 pm, Christian Zigotzky wrote:
> On 21 November 2019 at 01:16 pm, Christian Zigotzky wrote:
> > On 21 November 2019 at 08:29 am, Christoph Hellwig wrote:
> > > On Sat, Nov 16, 2019 at 08:06:05AM +0100, Christian Zigotzky wrote:
> > > > /*
> > > > Â *Â DMA addressing mode.
> > > > Â *
> > > > Â *Â 0 : 32 bit addressing for all chips.
> > > > Â *Â 1 : 40 bit addressing when supported by chip.
> > > > Â *Â 2 : 64 bit addressing when supported by chip,
> > > > Â *ÂÂÂÂÂ limited to 16 segments of 4 GB -> 64 GB max.
> > > > Â */
> > > > #defineÂÂ SYM_CONF_DMA_ADDRESSING_MODE 
> > > > CONFIG_SCSI_SYM53C8XX_DMA_ADDRESSING_MODE
> > > >
> > > > Cyrus config:
> > > >
> > > > CONFIG_SCSI_SYM53C8XX_DMA_ADDRESSING_MODE=1
> > > >
> > > > I will configure â0 : 32 bit addressing for all chipsâ 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@xxxxxxx/T/#u