[PATCH] usb: renesas_usbhs: fix signed-unsigned return

[PATCH] usb: renesas_usbhs: fix signed-unsigned return

[Sudip Mukherjee]

The return type of usbhsp_setup_pipecfg() was u16 but it was returning
a negative value (-EINVAL). Instead lets return a pointer to u16 which
will hold the value to be returned or in case of error, return the
error code in ERR_PTR.

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
---
 drivers/usb/renesas_usbhs/pipe.c | 38 +++++++++++++++++++++++++-------------
 1 file changed, 25 insertions(+), 13 deletions(-)

diff --git a/drivers/usb/renesas_usbhs/pipe.c b/drivers/usb/renesas_usbhs/pipe.c
index 78e9dba..00d595c 100644
--- a/drivers/usb/renesas_usbhs/pipe.c
+++ b/drivers/usb/renesas_usbhs/pipe.c
@@ -391,9 +391,9 @@ void usbhs_pipe_set_trans_count_if_bulk(struct usbhs_pipe *pipe, int len)
 /*
  *		pipe setup
  */
-static u16 usbhsp_setup_pipecfg(struct usbhs_pipe *pipe,
-				int is_host,
-				int dir_in)
+static u16 *usbhsp_setup_pipecfg(struct usbhs_pipe *pipe,
+				 int is_host,
+				 int dir_in)
 {
 	u16 type = 0;
 	u16 bfre = 0;
@@ -407,9 +407,13 @@ static u16 usbhsp_setup_pipecfg(struct usbhs_pipe *pipe,
 		[USB_ENDPOINT_XFER_INT]  = TYPE_INT,
 		[USB_ENDPOINT_XFER_ISOC] = TYPE_ISO,
 	};
+	u16 *result;
 
 	if (usbhs_pipe_is_dcp(pipe))
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
+	result = kmalloc(sizeof(u16), GFP_KERNEL);
+	if (!result)
+		return ERR_PTR(-ENOMEM);
 
 	/*
 	 * PIPECFG
@@ -451,14 +455,14 @@ static u16 usbhsp_setup_pipecfg(struct usbhs_pipe *pipe,
 
 	/* EPNUM */
 	epnum = 0; /* see usbhs_pipe_config_update() */
-
-	return	type	|
-		bfre	|
-		dblb	|
-		cntmd	|
-		dir	|
-		shtnak	|
-		epnum;
+	*result = type	 |
+		  bfre	 |
+		  dblb	 |
+		  cntmd	 |
+		  dir	 |
+		  shtnak |
+		  epnum;
+	return result;
 }
 
 static u16 usbhsp_setup_pipebuff(struct usbhs_pipe *pipe)
@@ -683,6 +687,7 @@ struct usbhs_pipe *usbhs_pipe_malloc(struct usbhs_priv *priv,
 	int is_host = usbhs_mod_is_host(priv);
 	int ret;
 	u16 pipecfg, pipebuf;
+	u16 *result;
 
 	pipe = usbhsp_get_pipe(priv, endpoint_type);
 	if (!pipe) {
@@ -702,7 +707,14 @@ struct usbhs_pipe *usbhs_pipe_malloc(struct usbhs_priv *priv,
 		return NULL;
 	}
 
-	pipecfg  = usbhsp_setup_pipecfg(pipe, is_host, dir_in);
+	result = usbhsp_setup_pipecfg(pipe, is_host, dir_in);
+	if (IS_ERR(result)) {
+		dev_err(dev, "can't setup pipe\n");
+		return NULL;
+	}
+	pipecfg = *result;
+	kfree(result);
+
 	pipebuf  = usbhsp_setup_pipebuff(pipe);
 
 	usbhsp_pipe_select(pipe);
-- 
1.9.1

RE: [PATCH] usb: renesas_usbhs: fix signed-unsigned return

[Yoshihiro Shimoda]

Hi,

> From: Sudip Mukherjee
> Sent: Saturday, April 09, 2016 12:05 AM
> 
> The return type of usbhsp_setup_pipecfg() was u16 but it was returning
> a negative value (-EINVAL). Instead lets return a pointer to u16 which
> will hold the value to be returned or in case of error, return the
> error code in ERR_PTR.

Thank you for the patch!
I also think this usbhsp_setup_pipecfg() should return error code using correct variable type.

However, I would like to avoid to use ERR_PTR and kmalloc() somehow because
I feel this patch is complex a little.
How about the usbhsp_setup_pipecfg() prototype is changed like the following?

static int usbhsp_setup_pipecfg(struct usbhs_pipe *pipe,
				int is_host, int dir_in, u16 *pipecfg);

Best regards,
Yoshihiro Shimoda

> Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
> ---
>  drivers/usb/renesas_usbhs/pipe.c | 38 +++++++++++++++++++++++++-------------
>  1 file changed, 25 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/usb/renesas_usbhs/pipe.c b/drivers/usb/renesas_usbhs/pipe.c
> index 78e9dba..00d595c 100644
> --- a/drivers/usb/renesas_usbhs/pipe.c
> +++ b/drivers/usb/renesas_usbhs/pipe.c
> @@ -391,9 +391,9 @@ void usbhs_pipe_set_trans_count_if_bulk(struct usbhs_pipe *pipe, int len)
>  /*
>   *		pipe setup
>   */
> -static u16 usbhsp_setup_pipecfg(struct usbhs_pipe *pipe,
> -				int is_host,
> -				int dir_in)
> +static u16 *usbhsp_setup_pipecfg(struct usbhs_pipe *pipe,
> +				 int is_host,
> +				 int dir_in)
>  {
>  	u16 type = 0;
>  	u16 bfre = 0;
> @@ -407,9 +407,13 @@ static u16 usbhsp_setup_pipecfg(struct usbhs_pipe *pipe,
>  		[USB_ENDPOINT_XFER_INT]  = TYPE_INT,
>  		[USB_ENDPOINT_XFER_ISOC] = TYPE_ISO,
>  	};
> +	u16 *result;
> 
>  	if (usbhs_pipe_is_dcp(pipe))
> -		return -EINVAL;
> +		return ERR_PTR(-EINVAL);
> +	result = kmalloc(sizeof(u16), GFP_KERNEL);
> +	if (!result)
> +		return ERR_PTR(-ENOMEM);
> 
>  	/*
>  	 * PIPECFG
> @@ -451,14 +455,14 @@ static u16 usbhsp_setup_pipecfg(struct usbhs_pipe *pipe,
> 
>  	/* EPNUM */
>  	epnum = 0; /* see usbhs_pipe_config_update() */
> -
> -	return	type	|
> -		bfre	|
> -		dblb	|
> -		cntmd	|
> -		dir	|
> -		shtnak	|
> -		epnum;
> +	*result = type	 |
> +		  bfre	 |
> +		  dblb	 |
> +		  cntmd	 |
> +		  dir	 |
> +		  shtnak |
> +		  epnum;
> +	return result;
>  }
> 
>  static u16 usbhsp_setup_pipebuff(struct usbhs_pipe *pipe)
> @@ -683,6 +687,7 @@ struct usbhs_pipe *usbhs_pipe_malloc(struct usbhs_priv *priv,
>  	int is_host = usbhs_mod_is_host(priv);
>  	int ret;
>  	u16 pipecfg, pipebuf;
> +	u16 *result;
> 
>  	pipe = usbhsp_get_pipe(priv, endpoint_type);
>  	if (!pipe) {
> @@ -702,7 +707,14 @@ struct usbhs_pipe *usbhs_pipe_malloc(struct usbhs_priv *priv,
>  		return NULL;
>  	}
> 
> -	pipecfg  = usbhsp_setup_pipecfg(pipe, is_host, dir_in);
> +	result = usbhsp_setup_pipecfg(pipe, is_host, dir_in);
> +	if (IS_ERR(result)) {
> +		dev_err(dev, "can't setup pipe\n");
> +		return NULL;
> +	}
> +	pipecfg = *result;
> +	kfree(result);
> +
>  	pipebuf  = usbhsp_setup_pipebuff(pipe);
> 
>  	usbhsp_pipe_select(pipe);
> --
> 1.9.1
> 
> --
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RE: [PATCH] usb: renesas_usbhs: fix signed-unsigned return

[Felipe Balbi]

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Hi,

Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> writes:
>> From: Sudip Mukherjee
>> Sent: Saturday, April 09, 2016 12:05 AM
>> 
>> The return type of usbhsp_setup_pipecfg() was u16 but it was returning
>> a negative value (-EINVAL). Instead lets return a pointer to u16 which
>> will hold the value to be returned or in case of error, return the
>> error code in ERR_PTR.
>
> Thank you for the patch!
> I also think this usbhsp_setup_pipecfg() should return error code using correct variable type.
>
> However, I would like to avoid to use ERR_PTR and kmalloc() somehow because
> I feel this patch is complex a little.
> How about the usbhsp_setup_pipecfg() prototype is changed like the following?
>
> static int usbhsp_setup_pipecfg(struct usbhs_pipe *pipe,
> 				int is_host, int dir_in, u16 *pipecfg);

IMO, this makes much more sense.

-- 
balbi

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Re: [PATCH] usb: renesas_usbhs: fix signed-unsigned return

[Sudip Mukherjee]

On Thursday 14 April 2016 04:25 PM, Felipe Balbi wrote:
>
> Hi,
>
> Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> writes:
>>> From: Sudip Mukherjee
>>> Sent: Saturday, April 09, 2016 12:05 AM
>>>
>>> The return type of usbhsp_setup_pipecfg() was u16 but it was returning
>>> a negative value (-EINVAL). Instead lets return a pointer to u16 which
>>> will hold the value to be returned or in case of error, return the
>>> error code in ERR_PTR.
>>
>> Thank you for the patch!
>> I also think this usbhsp_setup_pipecfg() should return error code using correct variable type.
>>
>> However, I would like to avoid to use ERR_PTR and kmalloc() somehow because
>> I feel this patch is complex a little.
>> How about the usbhsp_setup_pipecfg() prototype is changed like the following?
>>
>> static int usbhsp_setup_pipecfg(struct usbhs_pipe *pipe,
>> 				int is_host, int dir_in, u16 *pipecfg);
>
> IMO, this makes much more sense.

Infact, I thought about both these ways while making the patch but 
somehow I thought this one is a better but ofcourse the other way is 
much simpler.
I will post v2.

regards
sudip