Re: Hotplug issue with Marvell 6121

[Tejun Heo <tj@kernel.org>]

Hello,

On 03/11/2010 12:33 PM, Mark Lord wrote:
> On 03/10/10 21:32, Justin Maggard wrote:
>>
>> It's not the 1.5Gbps that is causing the problem.  It appears to be
>> the act of changing speeds.  I added "libata.force=3:1.5Gbps" to my
>> kernel command line, and hotplugs seemed to work fine on that port
>> (presumably due to the fact that libata EH won't change the link speed
>> limit if it's already at 1.5Gbps).  The other port on the controller
>> still had hotplug problems.  So everything seems to be pointing to the
>> Marvell controller having problems when you change speeds.
> ...
> 
> If it's like their non-AHCI controllers (sata_mv), then the chipset/phy
> could be very particular about the sequence/timing used when changing
> speeds.

BTW, if not allowing PHY speed adjustment is necessary, the correct
way to implement that is in ->port_start() by modifying
link->hw_sata_spd_limit.  But I really hope there's some other way to
solve this.

Thanks.

-- 
tejun