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

From: Christian Zigotzky
Date: Sat Nov 16 2019 - 02:06:57 EST


FYI: Source files of the Dawicontrol DC 2976 UW SCSI board (PCI): https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/scsi/sym53c8xx_2?h=v5.4-rc7

/*
* 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 â0 : 32 bit addressing for all chipsâ for the RC8. Maybe this is the solution.

> On 13. Nov 2019, at 12:02, Christoph Hellwig <hch@xxxxxx> wrote:
>
> Interesting. Give me some time to come up with a real fix, as drivers
> really should not mess with GFP flags for these allocations, and even
> if they did swiotlb is supposed to take care of any resulting problems.