On Fri, May 12, 2000 at 02:54:57PM -0400, WANG,YIDING (A-SanJose,ex1) wrote:
> I hope someone can help me on the follwing issue:
> 
> In aic7xxx.c code (also qla1280.h), driver locking is being used as needed
> for critical section protection.  It is defined as DRIVER_LOCK and
> DRIVER_UNLOCK pair.  However, the lock is only being used for LInux 2.1.95
> below.  Questions:
> 
> 1, Why the driver does not do locking for Linux 2.1.95 beyond (except
> spinlock in ISR)?
> 2, Does Linux version beyond 2.1.95 will do the locking automatically by
> just including two header files (spinlock.h, smp.h)?
> 3, If like most linux scsi drivers which not handling lock (except ISR) is
> accepted, does that mean either mutex lock is altomatically handled by Linux
> 2.1.95 and beyond, or simply include "smp.h" and :spinlock.h" will be
> enough?

Because since 2.1.95, the global spinlock io_request_lock is used to lock
the SCSI subsystem. All the locking is done by the mid-layer, before the low
level driver is even called. 
Exception: IRQ, which is directly routed to the driver's IRQ handler.

Regards,
-- 
Kurt Garloff  <[EMAIL PROTECTED]>                          Eindhoven, NL
GPG key: See mail header, key servers         Linux kernel development
SuSE GmbH, Nuernberg, FRG                               SCSI, Security

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