diff mbox series

[17/24] usb: host: xhci: Remove unused variable 'len'

Message ID 20210526130037.856068-18-lee.jones@linaro.org
State New
Headers show
Series Rid W=1 warnings from USB | expand

Commit Message

Lee Jones May 26, 2021, 1 p.m. UTC
Fixes the following W=1 kernel build warning(s):

 drivers/usb/host/xhci.c: In function ‘xhci_unmap_temp_buf’:
 drivers/usb/host/xhci.c:1349:15: warning: variable ‘len’ set but not used [-Wunused-but-set-variable]

Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>

---
 drivers/usb/host/xhci.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

-- 
2.31.1

Comments

Greg Kroah-Hartman May 27, 2021, 7:26 a.m. UTC | #1
On Wed, May 26, 2021 at 02:00:30PM +0100, Lee Jones wrote:
> Fixes the following W=1 kernel build warning(s):

> 

>  drivers/usb/host/xhci.c: In function ‘xhci_unmap_temp_buf’:

>  drivers/usb/host/xhci.c:1349:15: warning: variable ‘len’ set but not used [-Wunused-but-set-variable]

> 

> Cc: Mathias Nyman <mathias.nyman@intel.com>

> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

> Cc: linux-usb@vger.kernel.org

> Signed-off-by: Lee Jones <lee.jones@linaro.org>

> ---

>  drivers/usb/host/xhci.c | 9 ++++-----

>  1 file changed, 4 insertions(+), 5 deletions(-)

> 

> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

> index 27283654ca080..ac2a7d4288883 100644

> --- a/drivers/usb/host/xhci.c

> +++ b/drivers/usb/host/xhci.c

> @@ -1346,7 +1346,6 @@ static bool xhci_urb_temp_buffer_required(struct usb_hcd *hcd,

>  

>  static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)

>  {

> -	unsigned int len;

>  	unsigned int buf_len;

>  	enum dma_data_direction dir;

>  

> @@ -1362,10 +1361,10 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)

>  				 dir);

>  

>  	if (usb_urb_dir_in(urb))

> -		len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs,

> -					   urb->transfer_buffer,

> -					   buf_len,

> -					   0);

> +		sg_pcopy_from_buffer(urb->sg, urb->num_sgs,

> +				     urb->transfer_buffer,

> +				     buf_len,

> +				     0);


Sorry, but no, I keep rejecting this over and over, it needs to handle
the error handling properly and not paper over it like this :(

All the bots keep tripping up on it, you are not alone.

thanks,

greg k-h
Lee Jones May 27, 2021, 8:16 a.m. UTC | #2
On Thu, 27 May 2021, Greg Kroah-Hartman wrote:

> On Wed, May 26, 2021 at 02:00:30PM +0100, Lee Jones wrote:

> > Fixes the following W=1 kernel build warning(s):

> > 

> >  drivers/usb/host/xhci.c: In function ‘xhci_unmap_temp_buf’:

> >  drivers/usb/host/xhci.c:1349:15: warning: variable ‘len’ set but not used [-Wunused-but-set-variable]

> > 

> > Cc: Mathias Nyman <mathias.nyman@intel.com>

> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

> > Cc: linux-usb@vger.kernel.org

> > Signed-off-by: Lee Jones <lee.jones@linaro.org>

> > ---

> >  drivers/usb/host/xhci.c | 9 ++++-----

> >  1 file changed, 4 insertions(+), 5 deletions(-)

> > 

> > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

> > index 27283654ca080..ac2a7d4288883 100644

> > --- a/drivers/usb/host/xhci.c

> > +++ b/drivers/usb/host/xhci.c

> > @@ -1346,7 +1346,6 @@ static bool xhci_urb_temp_buffer_required(struct usb_hcd *hcd,

> >  

> >  static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)

> >  {

> > -	unsigned int len;

> >  	unsigned int buf_len;

> >  	enum dma_data_direction dir;

> >  

> > @@ -1362,10 +1361,10 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)

> >  				 dir);

> >  

> >  	if (usb_urb_dir_in(urb))

> > -		len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs,

> > -					   urb->transfer_buffer,

> > -					   buf_len,

> > -					   0);

> > +		sg_pcopy_from_buffer(urb->sg, urb->num_sgs,

> > +				     urb->transfer_buffer,

> > +				     buf_len,

> > +				     0);

> 

> Sorry, but no, I keep rejecting this over and over, it needs to handle

> the error handling properly and not paper over it like this :(


Will fix.

> All the bots keep tripping up on it, you are not alone.


-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
Mathias Nyman May 27, 2021, 9:23 a.m. UTC | #3
On 27.5.2021 11.16, Lee Jones wrote:
> On Thu, 27 May 2021, Greg Kroah-Hartman wrote:

> 

>> On Wed, May 26, 2021 at 02:00:30PM +0100, Lee Jones wrote:

>>> Fixes the following W=1 kernel build warning(s):

>>>

>>>  drivers/usb/host/xhci.c: In function ‘xhci_unmap_temp_buf’:

>>>  drivers/usb/host/xhci.c:1349:15: warning: variable ‘len’ set but not used [-Wunused-but-set-variable]

>>>

>>> Cc: Mathias Nyman <mathias.nyman@intel.com>

>>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

>>> Cc: linux-usb@vger.kernel.org

>>> Signed-off-by: Lee Jones <lee.jones@linaro.org>

>>> ---

>>>  drivers/usb/host/xhci.c | 9 ++++-----

>>>  1 file changed, 4 insertions(+), 5 deletions(-)

>>>

>>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

>>> index 27283654ca080..ac2a7d4288883 100644

>>> --- a/drivers/usb/host/xhci.c

>>> +++ b/drivers/usb/host/xhci.c

>>> @@ -1346,7 +1346,6 @@ static bool xhci_urb_temp_buffer_required(struct usb_hcd *hcd,

>>>  

>>>  static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)

>>>  {

>>> -	unsigned int len;

>>>  	unsigned int buf_len;

>>>  	enum dma_data_direction dir;

>>>  

>>> @@ -1362,10 +1361,10 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)

>>>  				 dir);

>>>  

>>>  	if (usb_urb_dir_in(urb))

>>> -		len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs,

>>> -					   urb->transfer_buffer,

>>> -					   buf_len,

>>> -					   0);

>>> +		sg_pcopy_from_buffer(urb->sg, urb->num_sgs,

>>> +				     urb->transfer_buffer,

>>> +				     buf_len,

>>> +				     0);

>>

>> Sorry, but no, I keep rejecting this over and over, it needs to handle

>> the error handling properly and not paper over it like this :(

> 

> Will fix.

> 

>> All the bots keep tripping up on it, you are not alone.

> 


This is getting a lot of attention. Something like this should fix it:

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 27283654ca08..306ab81421fd 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1361,12 +1361,16 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)
 				 urb->transfer_buffer_length,
 				 dir);
 
-	if (usb_urb_dir_in(urb))
+	if (usb_urb_dir_in(urb)) {
 		len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs,
 					   urb->transfer_buffer,
 					   buf_len,
 					   0);
-
+		if (len != buf_len) {
+			xhci_dbg(xhci, "Copy from tmp buf to urb sg list failed\n");
+			urb->actual_length = len;
+		}
+	}
 	urb->transfer_flags &= ~URB_DMA_MAP_SINGLE;
 	kfree(urb->transfer_buffer);
 	urb->transfer_buffer = NULL;
 
urb->actual_length is now properly set.
The debug level message will help me find the cause if we ever need
to debug oddly behaving devices.

Note this is a very rarly taken codepath for quirky xHC harware that
can't handle a specific sequence of buffer lengths queued.

I can write a proper commit message and push this forward

-Mathias
Greg Kroah-Hartman May 27, 2021, 9:50 a.m. UTC | #4
On Thu, May 27, 2021 at 12:23:24PM +0300, Mathias Nyman wrote:
> On 27.5.2021 11.16, Lee Jones wrote:

> > On Thu, 27 May 2021, Greg Kroah-Hartman wrote:

> > 

> >> On Wed, May 26, 2021 at 02:00:30PM +0100, Lee Jones wrote:

> >>> Fixes the following W=1 kernel build warning(s):

> >>>

> >>>  drivers/usb/host/xhci.c: In function ‘xhci_unmap_temp_buf’:

> >>>  drivers/usb/host/xhci.c:1349:15: warning: variable ‘len’ set but not used [-Wunused-but-set-variable]

> >>>

> >>> Cc: Mathias Nyman <mathias.nyman@intel.com>

> >>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

> >>> Cc: linux-usb@vger.kernel.org

> >>> Signed-off-by: Lee Jones <lee.jones@linaro.org>

> >>> ---

> >>>  drivers/usb/host/xhci.c | 9 ++++-----

> >>>  1 file changed, 4 insertions(+), 5 deletions(-)

> >>>

> >>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

> >>> index 27283654ca080..ac2a7d4288883 100644

> >>> --- a/drivers/usb/host/xhci.c

> >>> +++ b/drivers/usb/host/xhci.c

> >>> @@ -1346,7 +1346,6 @@ static bool xhci_urb_temp_buffer_required(struct usb_hcd *hcd,

> >>>  

> >>>  static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)

> >>>  {

> >>> -	unsigned int len;

> >>>  	unsigned int buf_len;

> >>>  	enum dma_data_direction dir;

> >>>  

> >>> @@ -1362,10 +1361,10 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)

> >>>  				 dir);

> >>>  

> >>>  	if (usb_urb_dir_in(urb))

> >>> -		len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs,

> >>> -					   urb->transfer_buffer,

> >>> -					   buf_len,

> >>> -					   0);

> >>> +		sg_pcopy_from_buffer(urb->sg, urb->num_sgs,

> >>> +				     urb->transfer_buffer,

> >>> +				     buf_len,

> >>> +				     0);

> >>

> >> Sorry, but no, I keep rejecting this over and over, it needs to handle

> >> the error handling properly and not paper over it like this :(

> > 

> > Will fix.

> > 

> >> All the bots keep tripping up on it, you are not alone.

> > 

> 

> This is getting a lot of attention. Something like this should fix it:

> 

> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

> index 27283654ca08..306ab81421fd 100644

> --- a/drivers/usb/host/xhci.c

> +++ b/drivers/usb/host/xhci.c

> @@ -1361,12 +1361,16 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)

>  				 urb->transfer_buffer_length,

>  				 dir);

>  

> -	if (usb_urb_dir_in(urb))

> +	if (usb_urb_dir_in(urb)) {

>  		len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs,

>  					   urb->transfer_buffer,

>  					   buf_len,

>  					   0);

> -

> +		if (len != buf_len) {

> +			xhci_dbg(xhci, "Copy from tmp buf to urb sg list failed\n");

> +			urb->actual_length = len;

> +		}

> +	}

>  	urb->transfer_flags &= ~URB_DMA_MAP_SINGLE;

>  	kfree(urb->transfer_buffer);

>  	urb->transfer_buffer = NULL;

>  

> urb->actual_length is now properly set.

> The debug level message will help me find the cause if we ever need

> to debug oddly behaving devices.

> 

> Note this is a very rarly taken codepath for quirky xHC harware that

> can't handle a specific sequence of buffer lengths queued.

> 

> I can write a proper commit message and push this forward


That looks good, I kept waiting for one of the people who kept trying to
report "build warning fixes" to do it right, but I'll gladly take it
from you as well :)

thanks,

greg k-h
Lee Jones May 27, 2021, 11:06 a.m. UTC | #5
On Thu, 27 May 2021, Mathias Nyman wrote:

> On 27.5.2021 11.16, Lee Jones wrote:

> > On Thu, 27 May 2021, Greg Kroah-Hartman wrote:

> > 

> >> On Wed, May 26, 2021 at 02:00:30PM +0100, Lee Jones wrote:

> >>> Fixes the following W=1 kernel build warning(s):

> >>>

> >>>  drivers/usb/host/xhci.c: In function ‘xhci_unmap_temp_buf’:

> >>>  drivers/usb/host/xhci.c:1349:15: warning: variable ‘len’ set but not used [-Wunused-but-set-variable]

> >>>

> >>> Cc: Mathias Nyman <mathias.nyman@intel.com>

> >>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

> >>> Cc: linux-usb@vger.kernel.org

> >>> Signed-off-by: Lee Jones <lee.jones@linaro.org>

> >>> ---

> >>>  drivers/usb/host/xhci.c | 9 ++++-----

> >>>  1 file changed, 4 insertions(+), 5 deletions(-)

> >>>

> >>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

> >>> index 27283654ca080..ac2a7d4288883 100644

> >>> --- a/drivers/usb/host/xhci.c

> >>> +++ b/drivers/usb/host/xhci.c

> >>> @@ -1346,7 +1346,6 @@ static bool xhci_urb_temp_buffer_required(struct usb_hcd *hcd,

> >>>  

> >>>  static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)

> >>>  {

> >>> -	unsigned int len;

> >>>  	unsigned int buf_len;

> >>>  	enum dma_data_direction dir;

> >>>  

> >>> @@ -1362,10 +1361,10 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)

> >>>  				 dir);

> >>>  

> >>>  	if (usb_urb_dir_in(urb))

> >>> -		len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs,

> >>> -					   urb->transfer_buffer,

> >>> -					   buf_len,

> >>> -					   0);

> >>> +		sg_pcopy_from_buffer(urb->sg, urb->num_sgs,

> >>> +				     urb->transfer_buffer,

> >>> +				     buf_len,

> >>> +				     0);

> >>

> >> Sorry, but no, I keep rejecting this over and over, it needs to handle

> >> the error handling properly and not paper over it like this :(

> > 

> > Will fix.

> > 

> >> All the bots keep tripping up on it, you are not alone.

> > 

> 

> This is getting a lot of attention. Something like this should fix it:

> 

> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

> index 27283654ca08..306ab81421fd 100644

> --- a/drivers/usb/host/xhci.c

> +++ b/drivers/usb/host/xhci.c

> @@ -1361,12 +1361,16 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)

>  				 urb->transfer_buffer_length,

>  				 dir);

>  

> -	if (usb_urb_dir_in(urb))

> +	if (usb_urb_dir_in(urb)) {

>  		len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs,

>  					   urb->transfer_buffer,

>  					   buf_len,

>  					   0);

> -

> +		if (len != buf_len) {

> +			xhci_dbg(xhci, "Copy from tmp buf to urb sg list failed\n");

> +			urb->actual_length = len;

> +		}

> +	}

>  	urb->transfer_flags &= ~URB_DMA_MAP_SINGLE;

>  	kfree(urb->transfer_buffer);

>  	urb->transfer_buffer = NULL;

>  

> urb->actual_length is now properly set.

> The debug level message will help me find the cause if we ever need

> to debug oddly behaving devices.

> 

> Note this is a very rarly taken codepath for quirky xHC harware that

> can't handle a specific sequence of buffer lengths queued.

> 

> I can write a proper commit message and push this forward


Okay by me.

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
diff mbox series

Patch

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 27283654ca080..ac2a7d4288883 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1346,7 +1346,6 @@  static bool xhci_urb_temp_buffer_required(struct usb_hcd *hcd,
 
 static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)
 {
-	unsigned int len;
 	unsigned int buf_len;
 	enum dma_data_direction dir;
 
@@ -1362,10 +1361,10 @@  static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)
 				 dir);
 
 	if (usb_urb_dir_in(urb))
-		len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs,
-					   urb->transfer_buffer,
-					   buf_len,
-					   0);
+		sg_pcopy_from_buffer(urb->sg, urb->num_sgs,
+				     urb->transfer_buffer,
+				     buf_len,
+				     0);
 
 	urb->transfer_flags &= ~URB_DMA_MAP_SINGLE;
 	kfree(urb->transfer_buffer);