On 17/05/2017 13:38, John Garry wrote:
On 17/05/2017 13:27, Arnd Bergmann wrote:
On Wed, May 17, 2017 at 12:49 PM, John Garry <john.garry@xxxxxxxxxx>
wrote:
> From: Xiang Chen <chenxiang66@xxxxxxxxxxxxx>
>
> For ECC 1bit error, logic can recover it, so we only print a warning.
> For ECC multi-bit and AXI bus fatal error, we panic.
>
> Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
> Signed-off-by: Xiang Chen <chenxiang66@xxxxxxxxxxxxx>
This one is tricky as there are conflicting requirements:
- For debugging purposes, you want to continue running the system
to figure out what exactly went wrong. Often enough, having the
kernel panic means you don't get to see the panic message because
console access is unavailable and you cannot log in any more
- For data consistency purposes you want to stop the system as
soon as there is any uncorrectable data error
I see that most scsi drivers don't ever call panic or BUG(), though
you already do so for v1 and v2 hw.
Maybe the SCSI maintainers can provide some more guidance here.
Arnd
.
Hi Arnd,
Actually latest code for v2 has been updated to do a controller reset,
and not panic, for unrecoverable error:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c?h=v4.12-rc1#n2926
We never got around to implementing controller reset for v1 as this
platform (hip05) is not used much anymore.
As for v3, we will change to to do same once controller reset is
implemented. I should have added this to the commit log.
Thanks,
John
It has come to light that hip08 RAS architecture requires handling
certain errors with firmware first model. I am not sure on the flow of
controller reset for fatal errors - I'm currently checking the details.
But it is not worth adding this non-critical patch and reverting it
later, so I'll omit this patch when sending the v6 patchset which
includes the fix for sloppy spinlock usage.
Thanks,
John
