Re: [PATCH libata:upstream] fix atapi_packet_task vs. intr race

[Jeff Garzik <jgarzik@pobox.com>]

Tejun Heo wrote:
>  Interrupts from devices sharing the same IRQ could cause
> ata_host_intr to finish commands being processed by atapi_packet_task
> if the commands are using ATA_PROT_ATAPI_NODATA or ATA_PROT_ATAPI_DMA
> protocol.  This is because libata interrupt handler is unaware that
> interrupts are not expected during that period.  This patch adds
> ATA_FLAG_NOINTR flag to tell the interrupt handler that we're not
> expecting interrupts.
> 
>  Note that once proper HSM is implemented for interrupt-driven PIO,
> this should be merged into it and this flag will be removed.
> 
> Signed-off-by: Tejun Heo <htejun@gmail.com>

Looks good except for two things:

* use spin_lock_irqsave()/spin_unlock_irqrestore(), not spin_lock_irq()

* need to audit every driver[1].  if it implements its own 
->irq_handler() hook, then you likely need to update the driver.

	Jeff


[1] drivers/scsi/ahci.c drivers/scsi/ata_*.c drivers/scsi/sata_*.[ch]