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From: David Woodhouse <dwmw2@infradead.org>
To: Alexandr Andreev <andreev@niisi.msk.ru>
Cc: "linux-mtd@lists.infrared.org" <linux-mtd@lists.infradead.org>
Subject: Re: Why timer interrupt is disabled?
Date: Mon, 28 May 2001 16:36:15 +0100	[thread overview]
Message-ID: <26581.991064175@redhat.com> (raw)
In-Reply-To: <3B12A202.3040409@niisi.msk.ru>


andreev@niisi.msk.ru said:
>  It may happen that one  CPU is reading and other CPU is writing data
> at the same time. So, the  flash memory can return status value
> instead of data, for example. Does  the chip->mutex lock provides
> necessary synchronization?

Yes. The flash driver is required to make that work correctly. The (blkdev)
request functions aren't required to be reentrant anyway, I believe.

> I look at the other block device drivers code and found, that
> io_request  handlers do sti() in some cases. If you still don`t want
> to do it, we  could use a softirq. In the do_fd_request(), the "bottom
> halves" is used  for example. We could use a "bottom halves" or even a
> tasklet in our  case. What do you think about this?

Take a look at the way it's done by the mtdblock device, with a kernel 
thread.

--
dwmw2

  reply	other threads:[~2001-05-28 15:52 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-05-25 23:20 Disabling interrupts before block device request call Alexandr Andreev
2001-05-25 22:01 ` Jens Axboe
2001-05-28 19:07   ` Why timer interrupt is disabled? Alexandr Andreev
2001-05-28 15:36     ` David Woodhouse [this message]
2001-05-28 19:24   ` Disabling interrupts before block device request call Alexandr Andreev
  -- strict thread matches above, loose matches on Subject: below --
2001-05-25 13:04 Why timer interrupt is disabled? andreev
2001-05-25 13:12 ` David Woodhouse
     [not found]   ` <3B0EE338.1000701@niisi.msk.ru>
2001-05-25 15:17     ` David Woodhouse
2001-05-26  0:17       ` Alexandr Andreev
2001-05-25 16:37         ` David Woodhouse
2001-05-25 17:06           ` Herman Oosthuysen
2001-05-26  1:31           ` Alexandr Andreev
2001-05-25 17:36             ` David Woodhouse

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