lkml.org 
[lkml]   [2011]   [May]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 01/16] hpsa: do readl after writel in main i/o path to ensure commands don't get lost.
From
Date
On Wed, 04 May 2011 11:37:35 MDT, Matthew Wilcox said:
> > This probably needs a comment like
> > /* don't care - dummy read just to force write posting to chipset */
> > or similar. I'm assuming it's just functioning as a barrier-type flush of some sort?
>
> It's a PCI write flush. It's not clear to me why it's needed here,
> though. The write will eventually get to the device; why we need to
> make the CPU wait around for it to actually get there doesn't make sense.

Exactly why I think it needs a one-liner comment. :)


[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2011-05-04 19:57    [W:0.053 / U:38.892 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site