On Sat, Sep 6, 2014 at 8:29 AM, K. Y. Srinivasan <kys@xxxxxxxxxxxxx> wrote: > > In win8 we have a feature that allows for interrupt driven flow management > for host/guest communication. For instance, if the host were blocked because > there was no space available in the ringbuffer, the host could request that the > guest send an interrupt when space becomes available in the ringbuffer (when > the guest drains the ringbuffer). > > While this feature was implemented in the guest a while ago, we had not > advertised that the guest supported this feature. This patch advertises > the support to the host. > > For pre-win8 hosts, this has no effect since the size of the ringbuffer > control structure has not changed and all changes have been backward > compatible - unused/reserved space has been used to implement this > feature. > > In this version of the patch I have cleaned up the commit log based on > feedback from Greg KH. > > Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> > --- > 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; > + This feature is enabled, do we need to reset pending_send_sz and reserved1[12], reserved1[4028] here? > ring_info->ring_size = buflen; > ring_info->ring_datasize = buflen - sizeof(struct hv_ring_buffer); > > -- > 1.7.4.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
