[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH] e1000e: Don't zero out buffer address in rx des

From: Jason Wang
Subject: Re: [Qemu-devel] [PATCH] e1000e: Don't zero out buffer address in rx descriptor
Date: Fri, 21 Oct 2016 10:01:30 +0800
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0

On 2016年10月18日 22:27, Kevin Wolf wrote:
Am 18.10.2016 um 16:10 hat Dmitry Fleytman geschrieben:
>     On 17 Oct 2016, at 01:35 AM, Kevin Wolf<address@hidden>  wrote:
>     The e1000e emulation zeroes out any used rx descriptor and then writes a
>     completely newly constructed value there. By doing this, it doesn't only
>     update the write-back area of the descriptors (as it's supposed to do),
>     but it also clears the buffer address, which real hardware doesn't do.
>     The spec explicitly mentions in chapter 7.1.8 that it is valid for a
>     driver to reuse a descriptor and only update the status field while
>     doing so, i.e. reusing the old buffer address:
>        If software statically allocates buffers, and uses memory read to
>        check for completed descriptors, it simply has to zero the status
>        byte in the descriptor to make it ready for reuse by hardware.
>     This patch fixes the behaviour to leave the buffer address in
>     descriptors unchanged even after the descriptor has been used.
>Hi Kevin,
>Reviewed-by: Dmitry Fleytman<address@hidden>
>Thanks for catching this!
Thanks, Dmitry!

I assume that your R-b implies that you don't send a pull request
yourself. If so, what's the process for getting the patch merged? Is
Jason going to pick it up normally or should I send a pull request of my

I've picked this in my tree.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]