From: Sanjay R Mehta <sanju.mehta@amd.com>
Date: Fri, 15 Feb 2019 09:21:19 +0000 (+0000)
Subject: NTB: ntb_perf: Clear stale values in doorbell and command SPAD register
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=12c023d7c32ae14254c8903f0466d37dea6d21ed;p=linux.git

NTB: ntb_perf: Clear stale values in doorbell and command SPAD register

when ntb_perf is unloaded, the command scratchpad register still
retains the last initialized value of PERF_CMD_INVAL. When ntb_perf
is re-loaded and reads peer command scratchpad register and it mis
interprets the peer state as initialized.

To avoid this, clearing the local side command scratchpad register
in perf_disable_service

Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
Acked-by: Allen Hubbe <allenbh@gmail.com>
Acked-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
---

diff --git a/drivers/ntb/test/ntb_perf.c b/drivers/ntb/test/ntb_perf.c
index 32a70b6491cd7..d028331558ea7 100644
--- a/drivers/ntb/test/ntb_perf.c
+++ b/drivers/ntb/test/ntb_perf.c
@@ -751,6 +751,14 @@ static void perf_disable_service(struct perf_ctx *perf)
 	for (pidx = 0; pidx < perf->pcnt; pidx++)
 		flush_work(&perf->peers[pidx].service);
 
+	for (pidx = 0; pidx < perf->pcnt; pidx++) {
+		struct perf_peer *peer = &perf->peers[pidx];
+
+		ntb_spad_write(perf->ntb, PERF_SPAD_CMD(peer->gidx), 0);
+	}
+
+	ntb_db_clear(perf->ntb, PERF_SPAD_NOTIFY(perf->gidx));
+
 	ntb_link_disable(perf->ntb);
 }