Re: [PATCH v3 RESEND] scsi: report 'INQUIRY result too short' once per host

From: Vitaly Kuznetsov
Date: Fri Oct 30 2015 - 08:56:46 EST


Hannes Reinecke <hare@xxxxxxx> writes:

> On 10/30/2015 12:40 PM, Vitaly Kuznetsov wrote:
>> Some host adapters (e.g. Hyper-V storvsc) are known for not respecting the
>> SPC-2/3/4 requirement for 'INQUIRY data (see table ...) shall contain at
>> least 36 bytes'. As a result we get tons on 'scsi 0:7:1:1: scsi scan:
>> INQUIRY result too short (5), using 36' messages on console. This can be
>> problematic for slow consoles. Introduce short_inquiry flag in struct
>> Scsi_Host to print the message once per host.
>>
>> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
>> ---
>> Changes since v3 RESEND:
>> - Sorry, I screwed up James address when sending 'v3 RESEND'.
>>
>> Changes since v3:
>> - no changes, this is just a RESEND.
>>
>> Changes since v2:
>> - This is a successor of previously sent (and still not merged) "scsi:
>> introduce short_inquiry flag for broken host adapters" patch. I'm not
>> particularly sure which solution is better but I'm leaning towards this
>> one as it doesn't require changes to adapter drivers.
>> ---
>> drivers/scsi/scsi_scan.c | 9 ++++++---
>> include/scsi/scsi_host.h | 3 +++
>> 2 files changed, 9 insertions(+), 3 deletions(-)
>>
> Why not printk_once?
> Should achieve the same result, and we're saving yet another flag...
>

It seems it makes sense to print this warning per-host (as we can have
many hosts) and not just once. It's hard to come up with a reasonable
message for printk_once() -- "some of your SCSI devices are buggy"
sounds to vague. Here we say "this particular scsi controller is buggy".

--
Vitaly
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