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From:   souradeep chakrabarti <schakrabarti@linux.microsoft.com>
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Cc:     stable@vger.kernel.org, schakrabarti@microsoft.com,
        Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>
Subject: [PATCH 2/2 V3 net] net: mana: Fix MANA VF unload when host is unresponsive
Date:   Mon, 26 Jun 2023 02:20:24 -0700
Message-Id: <1687771224-27162-1-git-send-email-schakrabarti@linux.microsoft.com>
In-Reply-To: <1687771098-26775-1-git-send-email-schakrabarti@linux.microsoft.com>
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From: Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>

This is the second part of the fix.

Also this patch adds a new attribute in mana_context, which gets set when
mana_hwc_send_request() hits a timeout because of host unresponsiveness.
This flag then helps to avoid the timeouts in successive calls.

Fixes: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f (net: mana: Add a driver for
Microsoft Azure Network Adapter)
Signed-off-by: Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>
---
V2 -> V3:
* Removed the initialization of vf_unload_timeout
* Splitted the patch in two.
* Fixed extra space from the commit message.
---
 drivers/net/ethernet/microsoft/mana/gdma_main.c  |  4 +++-
 drivers/net/ethernet/microsoft/mana/hw_channel.c | 12 +++++++++++-
 include/net/mana/mana.h                          |  2 ++
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c
index 8f3f78b68592..6411f01be0d9 100644
--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -946,10 +946,12 @@ int mana_gd_deregister_device(struct gdma_dev *gd)
 	struct gdma_context *gc = gd->gdma_context;
 	struct gdma_general_resp resp = {};
 	struct gdma_general_req req = {};
+	struct mana_context *ac;
 	int err;
 
 	if (gd->pdid == INVALID_PDID)
 		return -EINVAL;
+	ac = gd->driver_data;
 
 	mana_gd_init_req_hdr(&req.hdr, GDMA_DEREGISTER_DEVICE, sizeof(req),
 			     sizeof(resp));
@@ -957,7 +959,7 @@ int mana_gd_deregister_device(struct gdma_dev *gd)
 	req.hdr.dev_id = gd->dev_id;
 
 	err = mana_gd_send_request(gc, sizeof(req), &req, sizeof(resp), &resp);
-	if (err || resp.hdr.status) {
+	if ((err || resp.hdr.status) && !ac->vf_unload_timeout) {
 		dev_err(gc->dev, "Failed to deregister device: %d, 0x%x\n",
 			err, resp.hdr.status);
 		if (!err)
diff --git a/drivers/net/ethernet/microsoft/mana/hw_channel.c b/drivers/net/ethernet/microsoft/mana/hw_channel.c
index 9d1507eba5b9..492cb2c6e2cb 100644
--- a/drivers/net/ethernet/microsoft/mana/hw_channel.c
+++ b/drivers/net/ethernet/microsoft/mana/hw_channel.c
@@ -1,8 +1,10 @@
 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
 /* Copyright (c) 2021, Microsoft Corporation. */
 
+#include "asm-generic/errno.h"
 #include <net/mana/gdma.h>
 #include <net/mana/hw_channel.h>
+#include <net/mana/mana.h>
 
 static int mana_hwc_get_msg_index(struct hw_channel_context *hwc, u16 *msg_id)
 {
@@ -786,12 +788,19 @@ int mana_hwc_send_request(struct hw_channel_context *hwc, u32 req_len,
 	struct hwc_wq *txq = hwc->txq;
 	struct gdma_req_hdr *req_msg;
 	struct hwc_caller_ctx *ctx;
+	struct mana_context *ac;
 	u32 dest_vrcq = 0;
 	u32 dest_vrq = 0;
 	u16 msg_id;
 	int err;
 
 	mana_hwc_get_msg_index(hwc, &msg_id);
+	ac = hwc->gdma_dev->driver_data;
+	if (ac->vf_unload_timeout) {
+		dev_err(hwc->dev, "HWC: vport is already unloaded.\n");
+		err = -ETIMEDOUT;
+		goto out;
+	}
 
 	tx_wr = &txq->msg_buf->reqs[msg_id];
 
@@ -825,9 +834,10 @@ int mana_hwc_send_request(struct hw_channel_context *hwc, u32 req_len,
 		goto out;
 	}
 
-	if (!wait_for_completion_timeout(&ctx->comp_event, 30 * HZ)) {
+	if (!wait_for_completion_timeout(&ctx->comp_event, 5 * HZ)) {
 		dev_err(hwc->dev, "HWC: Request timed out!\n");
 		err = -ETIMEDOUT;
+		ac->vf_unload_timeout = true;
 		goto out;
 	}
 
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index 9eef19972845..5f5affdca1eb 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -358,6 +358,8 @@ struct mana_context {
 
 	u16 num_ports;
 
+	bool vf_unload_timeout;
+
 	struct mana_eq *eqs;
 
 	struct net_device *ports[MAX_PORTS_IN_MANA_DEV];
-- 
2.34.1