From: Vineeth Pillai Date: Fri, 21 Aug 2020 15:28:49 +0000 (+0000) Subject: hv_utils: drain the timesync packets on onchannelcallback X-Git-Tag: v5.15~2910^2~2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b46b4a8a57c377b72a98c7930a9f6969d2d4784e;p=platform%2Fkernel%2Flinux-starfive.git hv_utils: drain the timesync packets on onchannelcallback There could be instances where a system stall prevents the timesync packets to be consumed. And this might lead to more than one packet pending in the ring buffer. Current code empties one packet per callback and it might be a stale one. So drain all the packets from ring buffer on each callback. Signed-off-by: Vineeth Pillai Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20200821152849.99517-1-viremana@linux.microsoft.com Signed-off-by: Wei Liu --- diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c index 1f86e8d..a4e8d96 100644 --- a/drivers/hv/hv_util.c +++ b/drivers/hv/hv_util.c @@ -387,10 +387,23 @@ static void timesync_onchannelcallback(void *context) struct ictimesync_ref_data *refdata; u8 *time_txf_buf = util_timesynch.recv_buffer; - vmbus_recvpacket(channel, time_txf_buf, - HV_HYP_PAGE_SIZE, &recvlen, &requestid); + /* + * Drain the ring buffer and use the last packet to update + * host_ts + */ + while (1) { + int ret = vmbus_recvpacket(channel, time_txf_buf, + HV_HYP_PAGE_SIZE, &recvlen, + &requestid); + if (ret) { + pr_warn_once("TimeSync IC pkt recv failed (Err: %d)\n", + ret); + break; + } + + if (!recvlen) + break; - if (recvlen > 0) { icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[ sizeof(struct vmbuspipe_hdr)];