Re: [PATCH 07/11] NFC: pn533: improve cmd queue handling

[Samuel Ortiz]

Hi Michael,

On Thu, Apr 21, 2016 at 04:43:55PM +0200, Michael Thalmeier wrote:
> Make sure cmd is set before a frame is passed to the transport layer for
> sending. In addition pn533_send_async_complete checks if cmd is set before
> accessing its members.
> 
> Signed-off-by: Michael Thalmeier 
> ---
>  drivers/nfc/pn533/pn533.c | 54 
> +--
>  1 file changed, 34 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
> index d9c5583..d1cc70a 100644
> --- a/drivers/nfc/pn533/pn533.c
> +++ b/drivers/nfc/pn533/pn533.c
> @@ -383,26 +383,36 @@ static void pn533_build_cmd_frame(struct pn533 *dev, u8 
> cmd_code,
>  static int pn533_send_async_complete(struct pn533 *dev)
>  {
>   struct pn533_cmd *cmd = dev->cmd;
> - int status = cmd->status;
> + int rc = 0;
>  
> - struct sk_buff *req = cmd->req;
> - struct sk_buff *resp = cmd->resp;
> + if (cmd) {
if (!cmd) {
dev_dbg(dev->dev, "%s: cmd not set\n", __func__);
return rc;
}

would make the rest of the code more readable.

Cheers,
Samuel.

Re: [PATCH 07/11] NFC: pn533: improve cmd queue handling

[Samuel Ortiz]

Hi Michael,

On Thu, Apr 21, 2016 at 04:43:55PM +0200, Michael Thalmeier wrote:
> Make sure cmd is set before a frame is passed to the transport layer for
> sending. In addition pn533_send_async_complete checks if cmd is set before
> accessing its members.
> 
> Signed-off-by: Michael Thalmeier 
> ---
>  drivers/nfc/pn533/pn533.c | 54 
> +--
>  1 file changed, 34 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
> index d9c5583..d1cc70a 100644
> --- a/drivers/nfc/pn533/pn533.c
> +++ b/drivers/nfc/pn533/pn533.c
> @@ -383,26 +383,36 @@ static void pn533_build_cmd_frame(struct pn533 *dev, u8 
> cmd_code,
>  static int pn533_send_async_complete(struct pn533 *dev)
>  {
>   struct pn533_cmd *cmd = dev->cmd;
> - int status = cmd->status;
> + int rc = 0;
>  
> - struct sk_buff *req = cmd->req;
> - struct sk_buff *resp = cmd->resp;
> + if (cmd) {
if (!cmd) {
dev_dbg(dev->dev, "%s: cmd not set\n", __func__);
return rc;
}

would make the rest of the code more readable.

Cheers,
Samuel.

[PATCH 07/11] NFC: pn533: improve cmd queue handling

[Michael Thalmeier]

Make sure cmd is set before a frame is passed to the transport layer for
sending. In addition pn533_send_async_complete checks if cmd is set before
accessing its members.

Signed-off-by: Michael Thalmeier 
---
 drivers/nfc/pn533/pn533.c | 54 +--
 1 file changed, 34 insertions(+), 20 deletions(-)

diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
index d9c5583..d1cc70a 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -383,26 +383,36 @@ static void pn533_build_cmd_frame(struct pn533 *dev, u8 
cmd_code,
 static int pn533_send_async_complete(struct pn533 *dev)
 {
struct pn533_cmd *cmd = dev->cmd;
-   int status = cmd->status;
+   int rc = 0;
 
-   struct sk_buff *req = cmd->req;
-   struct sk_buff *resp = cmd->resp;
+   if (cmd) {
+   int status = cmd->status;
 
-   int rc;
+   struct sk_buff *req = cmd->req;
+   struct sk_buff *resp = cmd->resp;
 
-   dev_kfree_skb(req);
+   dev_kfree_skb(req);
 
-   if (status < 0) {
-   rc = cmd->complete_cb(dev, cmd->complete_cb_context,
- ERR_PTR(status));
-   dev_kfree_skb(resp);
-   goto done;
-   }
+   if (status < 0) {
+   rc = cmd->complete_cb(dev, cmd->complete_cb_context,
+ ERR_PTR(status));
+   dev_kfree_skb(resp);
+   goto done;
+   }
+
+   /* when no response is set we got interrupted */
+   if (!resp)
+   resp = ERR_PTR(-EINTR);
 
-   skb_pull(resp, dev->ops->rx_header_len);
-   skb_trim(resp, resp->len - dev->ops->rx_tail_len);
+   if (!IS_ERR(resp)) {
+   skb_pull(resp, dev->ops->rx_header_len);
+   skb_trim(resp, resp->len - dev->ops->rx_tail_len);
+   }
 
-   rc = cmd->complete_cb(dev, cmd->complete_cb_context, resp);
+   rc = cmd->complete_cb(dev, cmd->complete_cb_context, resp);
+   } else {
+   dev_dbg(dev->dev, "%s: cmd not set\n", __func__);
+   }
 
 done:
kfree(cmd);
@@ -434,12 +444,14 @@ static int __pn533_send_async(struct pn533 *dev, u8 
cmd_code,
mutex_lock(>cmd_lock);
 
if (!dev->cmd_pending) {
+   dev->cmd = cmd;
rc = dev->phy_ops->send_frame(dev, req);
-   if (rc)
+   if (rc) {
+   dev->cmd = NULL;
goto error;
+   }
 
dev->cmd_pending = 1;
-   dev->cmd = cmd;
goto unlock;
}
 
@@ -511,11 +523,12 @@ static int pn533_send_cmd_direct_async(struct pn533 *dev, 
u8 cmd_code,
 
pn533_build_cmd_frame(dev, cmd_code, req);
 
+   dev->cmd = cmd;
rc = dev->phy_ops->send_frame(dev, req);
-   if (rc < 0)
+   if (rc < 0) {
+   dev->cmd = NULL;
kfree(cmd);
-   else
-   dev->cmd = cmd;
+   }
 
return rc;
 }
@@ -550,14 +563,15 @@ static void pn533_wq_cmd(struct work_struct *work)
 
mutex_unlock(>cmd_lock);
 
+   dev->cmd = cmd;
rc = dev->phy_ops->send_frame(dev, cmd->req);
if (rc < 0) {
+   dev->cmd = NULL;
dev_kfree_skb(cmd->req);
kfree(cmd);
return;
}
 
-   dev->cmd = cmd;
 }
 
 struct pn533_sync_cmd_response {
-- 
2.5.5

[PATCH 07/11] NFC: pn533: improve cmd queue handling

[Michael Thalmeier]

Make sure cmd is set before a frame is passed to the transport layer for
sending. In addition pn533_send_async_complete checks if cmd is set before
accessing its members.

Signed-off-by: Michael Thalmeier 
---
 drivers/nfc/pn533/pn533.c | 54 +--
 1 file changed, 34 insertions(+), 20 deletions(-)

diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
index d9c5583..d1cc70a 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -383,26 +383,36 @@ static void pn533_build_cmd_frame(struct pn533 *dev, u8 
cmd_code,
 static int pn533_send_async_complete(struct pn533 *dev)
 {
struct pn533_cmd *cmd = dev->cmd;
-   int status = cmd->status;
+   int rc = 0;
 
-   struct sk_buff *req = cmd->req;
-   struct sk_buff *resp = cmd->resp;
+   if (cmd) {
+   int status = cmd->status;
 
-   int rc;
+   struct sk_buff *req = cmd->req;
+   struct sk_buff *resp = cmd->resp;
 
-   dev_kfree_skb(req);
+   dev_kfree_skb(req);
 
-   if (status < 0) {
-   rc = cmd->complete_cb(dev, cmd->complete_cb_context,
- ERR_PTR(status));
-   dev_kfree_skb(resp);
-   goto done;
-   }
+   if (status < 0) {
+   rc = cmd->complete_cb(dev, cmd->complete_cb_context,
+ ERR_PTR(status));
+   dev_kfree_skb(resp);
+   goto done;
+   }
+
+   /* when no response is set we got interrupted */
+   if (!resp)
+   resp = ERR_PTR(-EINTR);
 
-   skb_pull(resp, dev->ops->rx_header_len);
-   skb_trim(resp, resp->len - dev->ops->rx_tail_len);
+   if (!IS_ERR(resp)) {
+   skb_pull(resp, dev->ops->rx_header_len);
+   skb_trim(resp, resp->len - dev->ops->rx_tail_len);
+   }
 
-   rc = cmd->complete_cb(dev, cmd->complete_cb_context, resp);
+   rc = cmd->complete_cb(dev, cmd->complete_cb_context, resp);
+   } else {
+   dev_dbg(dev->dev, "%s: cmd not set\n", __func__);
+   }
 
 done:
kfree(cmd);
@@ -434,12 +444,14 @@ static int __pn533_send_async(struct pn533 *dev, u8 
cmd_code,
mutex_lock(>cmd_lock);
 
if (!dev->cmd_pending) {
+   dev->cmd = cmd;
rc = dev->phy_ops->send_frame(dev, req);
-   if (rc)
+   if (rc) {
+   dev->cmd = NULL;
goto error;
+   }
 
dev->cmd_pending = 1;
-   dev->cmd = cmd;
goto unlock;
}
 
@@ -511,11 +523,12 @@ static int pn533_send_cmd_direct_async(struct pn533 *dev, 
u8 cmd_code,
 
pn533_build_cmd_frame(dev, cmd_code, req);
 
+   dev->cmd = cmd;
rc = dev->phy_ops->send_frame(dev, req);
-   if (rc < 0)
+   if (rc < 0) {
+   dev->cmd = NULL;
kfree(cmd);
-   else
-   dev->cmd = cmd;
+   }
 
return rc;
 }
@@ -550,14 +563,15 @@ static void pn533_wq_cmd(struct work_struct *work)
 
mutex_unlock(>cmd_lock);
 
+   dev->cmd = cmd;
rc = dev->phy_ops->send_frame(dev, cmd->req);
if (rc < 0) {
+   dev->cmd = NULL;
dev_kfree_skb(cmd->req);
kfree(cmd);
return;
}
 
-   dev->cmd = cmd;
 }
 
 struct pn533_sync_cmd_response {
-- 
2.5.5