diff mbox series

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

Message ID 20210526130037.856068-18-lee.jones@linaro.org (mailing list archive)
State New, archived
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(-)

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.
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.
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);