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

From: Robin Murphy
Date: Thu Nov 21 2019 - 08:33:58 EST


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:
/*
 * 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.
 */
#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