> -----Original Message----- > From: James Bottomley [mailto:james.bottom...@hansenpartnership.com] > Sent: Wednesday, October 24, 2012 6:25 PM > To: KY Srinivasan > Cc: gre...@linuxfoundation.org; linux-ker...@vger.kernel.org; > de...@linuxdriverproject.org; oher...@suse.com; h...@infradead.org; linux- > s...@vger.kernel.org > Subject: Re: Drivers: scsi > > On Wed, 2012-10-24 at 09:25 -0700, K. Y. Srinivasan wrote: > > When the low level driver returns SCSI_MLQUEUE_DEVICE_BUSY, > > how is the command retried; I suspect the retry is done after some delay. > > Delay depends mainly on I/O pressure and the unplug timer in the block > layer. > > > Is this delay programmable? If the device state changes, > > can the low level driver notify upper layers that it can now handle > > the command that it had failed earlier with SCSI_MLQUEUE_DEVICE_BUSY. > > In theory, you can call blk_run_queue() from the event handler that sees > the device become ready. I don't think any driver actually does this, > but I can't see it would cause any problem.
I will try this. Thanks for your prompt response. Regards, K. Y
