From: Boqun Feng <boqun.feng@xxxxxxxxx> Sent: Tuesday, September 15, 2020 8:48 PM > > For a Hyper-V vmbus, the size of the ringbuffer has two requirements: > > 1) it has to take one PAGE_SIZE for the header > > 2) it has to be PAGE_SIZE aligned so that double-mapping can work > > VMBUS_RING_SIZE() could calculate a correct ringbuffer size which > fulfills both requirements, therefore use it to make sure vmbus work > when PAGE_SIZE != HV_HYP_PAGE_SIZE (4K). > > Note that since the argument for VMBUS_RING_SIZE() is the size of > payload (data part), so it will be minus 4k (the size of header when > PAGE_SIZE = 4k) than the original value to keep the ringbuffer total > size unchanged when PAGE_SIZE = 4k. > > Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx> > Cc: Jiri Kosina <jkosina@xxxxxxx> > Cc: Michael Kelley <mikelley@xxxxxxxxxxxxx> > --- > Michael and Jiri, > > I change the code because of a problem I found: > > https://lore.kernel.org/lkml/20200914084600.GA45838@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > > , so I drop your Reviewed-by or Acked-by tag. If the update version > looks good to you, may I add your tag again? Thanks in advance, and > apologies for the inconvenience. > > Regards, > Boqun > > drivers/hid/hid-hyperv.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/hid/hid-hyperv.c b/drivers/hid/hid-hyperv.c > index 0b6ee1dee625..978ee2aab2d4 100644 > --- a/drivers/hid/hid-hyperv.c > +++ b/drivers/hid/hid-hyperv.c > @@ -104,8 +104,8 @@ struct synthhid_input_report { > > #pragma pack(pop) > > -#define INPUTVSC_SEND_RING_BUFFER_SIZE (40 * 1024) > -#define INPUTVSC_RECV_RING_BUFFER_SIZE (40 * 1024) > +#define INPUTVSC_SEND_RING_BUFFER_SIZE VMBUS_RING_SIZE(36 * 1024) > +#define INPUTVSC_RECV_RING_BUFFER_SIZE VMBUS_RING_SIZE(36 * 1024) > > > enum pipe_prot_msg_type { > -- > 2.28.0 Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
