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* scsi_add_host() context
@ 2002-11-18  1:26 Douglas Gilbert
  2002-11-19  0:02 ` Christoph Hellwig
  0 siblings, 1 reply; 2+ messages in thread
From: Douglas Gilbert @ 2002-11-18  1:26 UTC (permalink / raw)
  To: linux-scsi; +Cc: hch

While examining the various calls in the mid level that
can be called from a LLD, most are designed to
be called from an interrupt or related context
(e.g. scsi_adjust_queue_depth() ).

However, the detection of a new host requires a LLD to call 
scsi_register() and scsi_add_host(). The latter call does
a SCSI bus scan which takes time and sends commands like
INQUIRY and REPORT_LUNS back through the LLD. So scsi_add_host()
should not be called from an interrupt context. Can this be
guaranteed in a hotplug environment? Is a worker thread
required?

Doug Gilbert


^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: scsi_add_host() context
  2002-11-18  1:26 scsi_add_host() context Douglas Gilbert
@ 2002-11-19  0:02 ` Christoph Hellwig
  0 siblings, 0 replies; 2+ messages in thread
From: Christoph Hellwig @ 2002-11-19  0:02 UTC (permalink / raw)
  To: Douglas Gilbert; +Cc: linux-scsi

On Mon, Nov 18, 2002 at 12:26:38PM +1100, Douglas Gilbert wrote:
> While examining the various calls in the mid level that
> can be called from a LLD, most are designed to
> be called from an interrupt or related context
> (e.g. scsi_adjust_queue_depth() ).
> 
> However, the detection of a new host requires a LLD to call 
> scsi_register() and scsi_add_host(). The latter call does
> a SCSI bus scan which takes time and sends commands like
> INQUIRY and REPORT_LUNS back through the LLD. So scsi_add_host()
> should not be called from an interrupt context. Can this be
> guaranteed in a hotplug environment? Is a worker thread
> required?

For the driver model ->probe is defined to run in process context, yes.


^ permalink raw reply	[flat|nested] 2+ messages in thread

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