Re: [PATCH 1/1] pci: Block config access during BIST (resend)

From: Benjamin Herrenschmidt (benh_at_kernel.crashing.org)
Date: 01/26/05

  • Next message: Albert Herranz: "[PATCH 2.6.11-rc2-mm1] perfctl-ppc: fix duplicate mmcr0 define"
    To: brking@us.ibm.com
    Date:	Thu, 27 Jan 2005 09:10:05 +1100
    
    

    On Wed, 2005-01-26 at 10:34 -0600, Brian King wrote:

    > Here is the last one. I've looked at making userspace sleep until BIST
    > is finished. The downside I see to this is that is complicates the patch
    > due to the following reasons:
    >
    > 1. In order to also make this work for Ben's PPC power management usage
    > would require an additional flag and additional APIs to set and clear
    > the flag.
    > 2. Since BIST can be run at interrupt context, the interfaces to block
    > and unblock userspace accesses across BIST must be callable from
    > interrupt context. This prevents the usage of semaphores or simple
    > wait_event macros and requires new macros that carefully check the new
    > pci device flag and manage the spinlock.
    >

    Well, I honestly think that this is unnecessary burden. I think that
    just dropping writes & returning data from the cache on reads is enough,
    blocking userspace isn't necessary, but then, I may be wrong ;)

    Ben.

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  • Next message: Albert Herranz: "[PATCH 2.6.11-rc2-mm1] perfctl-ppc: fix duplicate mmcr0 define"

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