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From: Clemens Ladisch <clemens@ladisch.de>
To: Raimonds Cicans <ray@apollo.lv>, linux-kernel@vger.kernel.org
Subject: Re: Questions about IOMMU & PCIe switch
Date: Wed, 07 Jan 2015 13:09:06 +0100	[thread overview]
Message-ID: <54AD21E2.2020100@ladisch.de> (raw)
In-Reply-To: <54ACB0D4.3000008@apollo.lv>

Raimonds Cicans wrote:
> We have two kinds of PCIe cards:
> A1 - based on chip B
> A2 - based on same chip B but behind PCIe switch
>
> Card A1 work flawlessly in any configuration,
> but card A2 work flawlessly only if system
> lack IOMMU or have disabled IOMMU

In theory, such a switch should be transparent.

> Do we have to treat card with PCIe switch in special way?

No.  But the switch has to work correctly, and driver must be
written correctly.

Which switch?  Which driver?


Regards,
Clemens

  reply	other threads:[~2015-01-07 12:14 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-07  4:06 Questions about IOMMU & PCIe switch Raimonds Cicans
2015-01-07 12:09 ` Clemens Ladisch [this message]
2015-01-07 14:04   ` Raimonds Cicans
2015-01-08  8:34     ` Clemens Ladisch
2015-01-08 15:05       ` Raimonds Cicans
2015-01-08 15:32         ` Manu Abraham
  -- strict thread matches above, loose matches on Subject: below --
2015-01-15 12:54 Luis Alves

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