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From: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
To: kvalo@codeaurora.org
Cc: johannes@sipsolutions.net, linux-wireless@vger.kernel.org,
	luca@coelho.fi, Tomas Winkler <tomas.winkler@intel.com>,
	Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Subject: [PATCH 1/5] mei: allow map and unmap of client dma buffer only for disconnected client
Date: Mon, 22 Mar 2021 22:46:29 +0200	[thread overview]
Message-ID: <20210322204633.102581-2-emmanuel.grumbach@intel.com> (raw)
In-Reply-To: <20210322204633.102581-1-emmanuel.grumbach@intel.com>

From: Tomas Winkler <tomas.winkler@intel.com>

Allow map and unmap of the client dma buffer only when the client is not
connected. The functions return -EPROTO if the client is already connected.
This is to fix the race when traffic may start or stop when buffer
is not available.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
---
 drivers/misc/mei/client.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 4378a9b25848..2cc370adb238 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -2286,8 +2286,8 @@ int mei_cl_dma_alloc_and_map(struct mei_cl *cl, const struct file *fp,
 	if (buffer_id == 0)
 		return -EINVAL;
 
-	if (!mei_cl_is_connected(cl))
-		return -ENODEV;
+	if (mei_cl_is_connected(cl))
+		return -EPROTO;
 
 	if (cl->dma_mapped)
 		return -EPROTO;
@@ -2327,9 +2327,7 @@ int mei_cl_dma_alloc_and_map(struct mei_cl *cl, const struct file *fp,
 
 	mutex_unlock(&dev->device_lock);
 	wait_event_timeout(cl->wait,
-			   cl->dma_mapped ||
-			   cl->status ||
-			   !mei_cl_is_connected(cl),
+			   cl->dma_mapped || cl->status,
 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 	mutex_lock(&dev->device_lock);
 
@@ -2376,8 +2374,9 @@ int mei_cl_dma_unmap(struct mei_cl *cl, const struct file *fp)
 		return -EOPNOTSUPP;
 	}
 
-	if (!mei_cl_is_connected(cl))
-		return -ENODEV;
+	/* do not allow unmap for connected client */
+	if (mei_cl_is_connected(cl))
+		return -EPROTO;
 
 	if (!cl->dma_mapped)
 		return -EPROTO;
@@ -2405,9 +2404,7 @@ int mei_cl_dma_unmap(struct mei_cl *cl, const struct file *fp)
 
 	mutex_unlock(&dev->device_lock);
 	wait_event_timeout(cl->wait,
-			   !cl->dma_mapped ||
-			   cl->status ||
-			   !mei_cl_is_connected(cl),
+			   !cl->dma_mapped || cl->status,
 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 	mutex_lock(&dev->device_lock);
 
-- 
2.25.1


  reply	other threads:[~2021-03-22 20:47 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-22 20:46 [RESEND PATCH 0/5] Add support for AMT over WLAN Emmanuel Grumbach
2021-03-22 20:46 ` Emmanuel Grumbach [this message]
2021-03-23 15:15   ` [PATCH 1/5] mei: allow map and unmap of client dma buffer only for disconnected client Emmanuel Grumbach
2021-03-22 20:46 ` [PATCH 2/5] mei: bus: add client dma interface Emmanuel Grumbach
2021-03-22 20:46 ` [PATCH 3/5] cfg80211: allow to specifying a reason for hw_rfkill Emmanuel Grumbach
2021-03-22 20:46 ` [PATCH 4/5] iwlwifi: mei: add the driver to allow cooperation with CSME Emmanuel Grumbach
2021-03-22 20:46 ` [PATCH 5/5] iwlwifi: integrate with iwlmei Emmanuel Grumbach
  -- strict thread matches above, loose matches on Subject: below --
2021-03-22 20:41 [PATCH 0/5] Add support for AMT over WLAN Emmanuel Grumbach
2021-03-22 20:41 ` [PATCH 1/5] mei: allow map and unmap of client dma buffer only for disconnected client Emmanuel Grumbach

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