xenfb: use the correct condition to avoid excessive looping

In commit ac0487e1 ("xenfb.c: avoid expensive loops when prod <=
out_cons"), ">=" was used. In fact, a full ring is a legit state.
Correct the test to use ">".

Reported-by: "Hao, Xudong" <xudong.hao@intel.com>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Tested-by: "Hao, Xudong" <xudong.hao@intel.com>
Acked-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
This commit is contained in:
Wei Liu 2016-04-12 11:43:14 +01:00 committed by Stefano Stabellini
parent 42bb626f7e
commit 4df26e88ee

View file

@ -775,7 +775,7 @@ static void xenfb_handle_events(struct XenFB *xenfb)
prod = page->out_prod;
out_cons = page->out_cons;
if (prod - out_cons >= XENFB_OUT_RING_LEN) {
if (prod - out_cons > XENFB_OUT_RING_LEN) {
return;
}
xen_rmb(); /* ensure we see ring contents up to prod */