From: Alex Williamson <alex.williamson@redhat.com>
To: shiv prakash Agarwal <chhotu.shiv@gmail.com>
Cc: "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>,
Pratyush Anand <pratyush.anand@st.com>,
Yinghai Lu <yinghai@kernel.org>
Subject: Re: Writing to BARs of PCIE device
Date: Thu, 03 Apr 2014 09:23:10 -0600 [thread overview]
Message-ID: <1396538590.3215.6.camel@ul30vt.home> (raw)
In-Reply-To: <CAHH3p5LwsWqtK_RhaYNKi_HeNYH3EHrgXV21SbRTA4mm2Vyjwg@mail.gmail.com>
On Thu, 2014-04-03 at 20:38 +0530, shiv prakash Agarwal wrote:
> Hi All,
>
> I have a stress test which write a specific 4B pattern to whole BAR
> space for all BARs of a pcie device.
>
> Query is:
>
> 1. Is it allowed? Or will it have any side-effects?
> 2. If No, is it not allowed for all BARs or some BARs only like BAR0?
Of course it will have side-effects, it's conceptually the same as
'cat /dev/random > /dev/mem', but for a device instead of the kernel.
What you're overwriting is device dependent, but in any case you're
trashing something. The test sounds completely invalid to me. Thanks,
Alex
next prev parent reply other threads:[~2014-04-03 15:23 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-03 15:08 Writing to BARs of PCIE device shiv prakash Agarwal
2014-04-03 15:23 ` Alex Williamson [this message]
2014-04-04 6:14 ` shiv prakash Agarwal
2014-04-04 11:57 ` Andrew Murray
2014-04-09 11:32 ` shiv prakash Agarwal
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