From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751721AbaIETLu (ORCPT ); Fri, 5 Sep 2014 15:11:50 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:41535 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750744AbaIETLt (ORCPT ); Fri, 5 Sep 2014 15:11:49 -0400 Date: Fri, 5 Sep 2014 12:11:48 -0700 From: Greg KH To: "K. Y. Srinivasan" Cc: linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com Subject: Re: [PATCH 1/1] Drivers: hv: vmbus: Enable interrupt driven flow control Message-ID: <20140905191148.GA24879@kroah.com> References: <1409941402-486-1-git-send-email-kys@microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1409941402-486-1-git-send-email-kys@microsoft.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 05, 2014 at 11:23:22AM -0700, K. Y. Srinivasan wrote: > This is a win8 feature that has been implemented. Turn on the feature bit > to enable the feature. What does those two sentances even mean? > With this feature turned on, What is "this"? > when the host is waiting > for space to become available on the ringbuffer (host to guest), the guest > will interrupt the host when space becomes available (as part of draining > the ring buffer). > > Signed-off-by: K. Y. Srinivasan > --- > drivers/hv/ring_buffer.c | 5 +++++ > 1 files changed, 5 insertions(+), 0 deletions(-) > > diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c > index 15db66b..6361d12 100644 > --- a/drivers/hv/ring_buffer.c > +++ b/drivers/hv/ring_buffer.c > @@ -361,6 +361,11 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, > ring_info->ring_buffer->read_index = > ring_info->ring_buffer->write_index = 0; > > + /* > + * Set the feature bit for enabling flow control. > + */ > + ring_info->ring_buffer->feature_bits.value = 1; What happens if you are running on an old system that doesn't support this new "feature"? thanks, greg k-h