From: David Miller <davem@davemloft.net>
To: sshah@solarflare.com
Cc: netdev@vger.kernel.org, linux-net-drivers@solarflare.com
Subject: Re: [PATCH net v2 0/2] sfc: Restrict PIO for 64bit arch in order to avoid data corruption
Date: Fri, 30 May 2014 17:38:20 -0700 (PDT) [thread overview]
Message-ID: <20140530.173820.494414338220972060.davem@davemloft.net> (raw)
In-Reply-To: <5385AAF5.7090001@solarflare.com>
From: Shradha Shah <sshah@solarflare.com>
Date: Wed, 28 May 2014 10:23:01 +0100
> This patch series
> Fixes: ee45fd92c739db5b7950163d91dfe5f016af6d24
>
> The linux net driver uses memcpy_toio() in order to copy into
> the PIO buffers.
> Even on a 64bit machine this causes 32bit accesses to a write-
> combined memory region.
> There are hardware limitations that mean that only
> 64bit naturally aligned accesses are safe in all cases. Due to being
> write-combined memory region two 32bit accesses may be coalesced to
> form a 64bit non 64bit aligned access.
> Solution was to open-code the memory copy routines using pointers
> and to only enable PIO for x86_64 machines.
>
> This bug fix applies to v3.13 and v3.14 stable branches.
You submited this twice and I'm still confused which ones I should
use.
Please resubmit this and address Sergei's feedback, thank you.
prev parent reply other threads:[~2014-05-31 0:38 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-28 9:23 [PATCH net v2 0/2] sfc: Restrict PIO for 64bit arch in order to avoid data corruption Shradha Shah
2014-05-28 9:28 ` [PATCH net v2 1/2] sfc: use 64-bit writes for PIO Shradha Shah
2014-05-28 9:30 ` [PATCH net v2 2/2] sfc: Restrict PIO to 64-bit architectures Shradha Shah
2014-05-31 0:38 ` David Miller [this message]
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