ufs-bsg node not created

ufs-bsg node not created

[Tom Psyborg]

Hi

I'm trying to use the ufs-bsg transport for SSD debug tool and facing
an issue where there is no ufs-bsg node created either in /dev or
/dev/bsg.

Tried on live Ubuntu 20.04, and Ubuntu 16.04.6 installation with
custom built kernel 5.6.14.
Additionaly, tried rebuilding with [PATCH v2 0/3] Modulize ufs-bsg
series, I can modprobe ufs-bsg, ufs, bsg modules, still no ufs-bsg
node gets created.

Is there some other module that needs to get loaded?

Thanks, Tom

RE: ufs-bsg node not created

[Avri Altman]

Hi Tom,
 
> 
> Hi
> 
> I'm trying to use the ufs-bsg transport for SSD debug tool and facing
> an issue where there is no ufs-bsg node created either in /dev or
> /dev/bsg.
ufs-bsg is a bsg node designed to communicate with a ufs devices,
using non-scsi commands, but a ufs-specific protocol, which your ssd doesn't speak.
So you can't use it with any non-ufs devices.
To create it you need to open its config switch - CONFIG_SCSI_UFS_BSG.

Maybe try using the sg driver?

Thanks,
Avri

> 
> Tried on live Ubuntu 20.04, and Ubuntu 16.04.6 installation with
> custom built kernel 5.6.14.
> Additionaly, tried rebuilding with [PATCH v2 0/3] Modulize ufs-bsg
> series, I can modprobe ufs-bsg, ufs, bsg modules, still no ufs-bsg
> node gets created.
> 
> Is there some other module that needs to get loaded?
> 
> Thanks, Tom

Re: ufs-bsg node not created

[Tom Psyborg]

On 28/06/2020, Avri Altman <Avri.Altman@wdc.com> wrote:
> Hi Tom,
>
>>
>> Hi
>>
>> I'm trying to use the ufs-bsg transport for SSD debug tool and facing
>> an issue where there is no ufs-bsg node created either in /dev or
>> /dev/bsg.
> ufs-bsg is a bsg node designed to communicate with a ufs devices,
> using non-scsi commands, but a ufs-specific protocol, which your ssd doesn't
> speak.
> So you can't use it with any non-ufs devices.
> To create it you need to open its config switch - CONFIG_SCSI_UFS_BSG.
>
> Maybe try using the sg driver?
>
> Thanks,
> Avri
>
>

CONFIG_BLK_DEV_BSG, CONFIG_BLK_DEV_BSGLIB, CONFIG_SCSI_UFS_BSG were
already enabled.
Issuing a firmware info command but passing /dev/sda as a node
returned expected result, so the drive is at least partially supported
by the tool.
Anyway, after inspection of the drive with DMM the point of failure
appears to be at hardware level so the tool won't be much of a use.
It's Micron M600 m2 disk btw.

Thanks, Tom