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SubjectRe: [PATCH v2 1/7] scsi: libsas: reset the negotiated_linkrate when phy is down
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On 2019/1/30 21:08, John Garry wrote:
> On 30/01/2019 08:24, Jason Yan wrote:
>> If the device is unplugged or disconnected, the negotiated_linkrate
>> still can be seen from the userspace by sysfs. This makes people
>> confused and leaks information of the device last used. So let's reset
>> the negotiated_linkrate after the phy is down.
>>
>> Signed-off-by: Jason Yan <yanaijie@huawei.com>
>> CC: John Garry <john.garry@huawei.com>
>> CC: Johannes Thumshirn <jthumshirn@suse.de>
>> CC: Ewan Milne <emilne@redhat.com>
>> CC: Christoph Hellwig <hch@lst.de>
>> CC: Tomas Henzl <thenzl@redhat.com>
>> CC: Dan Williams <dan.j.williams@intel.com>
>> CC: Hannes Reinecke <hare@suse.com>
>> ---
>> drivers/scsi/libsas/sas_expander.c | 2 ++
>> include/scsi/libsas.h | 3 +++
>> 2 files changed, 5 insertions(+)
>>
>> diff --git a/drivers/scsi/libsas/sas_expander.c
>> b/drivers/scsi/libsas/sas_expander.c
>> index 17eb4185f29d..7b0e6dcef6e6 100644
>> --- a/drivers/scsi/libsas/sas_expander.c
>> +++ b/drivers/scsi/libsas/sas_expander.c
>> @@ -1904,6 +1904,8 @@ static void sas_unregister_devs_sas_addr(struct
>> domain_device *parent,
>> &parent->port->sas_port_del_list);
>> phy->port = NULL;
>> }
>> + if (phy->phy)
>> + phy->phy->negotiated_linkrate = SAS_LINK_RATE_UNKNOWN;
>
> Does this work for both PHYs which were either directly attached or just
> forming part of a wideport?
>
> Please also note that the expander PHY which was previously attached may
> also show the incorrect value.

Good catch, all PHYs need to do this, not only the last PHY of the wideport.

>
>> }
>>
>> static int sas_discover_bfs_by_root_level(struct domain_device *root,
>> diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
>> index 3de3b10da19a..420156cea3ee 100644
>> --- a/include/scsi/libsas.h
>> +++ b/include/scsi/libsas.h
>> @@ -448,6 +448,9 @@ static inline void sas_phy_disconnected(struct
>> asd_sas_phy *phy)
>> {
>> phy->oob_mode = OOB_NOT_CONNECTED;
>> phy->linkrate = SAS_LINK_RATE_UNKNOWN;
>> +
>
> Then idea behind sas_phy_disconnected() was to set root PHY values only:
>
> /* Before calling a notify event, LLDD should use this function
> * when the link is severed (possibly from its tasklet).
> * The idea is that the Class only reads those, while the LLDD,
> * can R/W these (thus avoiding a race)
>
> libsas does set sas_phy negotiated_linkrate (but only for expander
> PHYs), so not the perfect place to set this. I'm nitpicking a bit here.
>

I don't want to put it here. I asked chenxiang to fix this in LLDD, but
he insist libsas to do this. Would you please discuss with chenxiang and
come to an agreement?

>
>> + if (phy->phy)
>> + phy->phy->negotiated_linkrate = SAS_LINK_RATE_UNKNOWN;
>> }
>>
>> static inline unsigned int to_sas_gpio_od(int device, int bit)
>
> Thanks,
>
>>
>
>
>
>
>
> .
>

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