| Message ID | 20210306120644.74406-1-zhangkun4jr@163.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | xhci: Remove unused value len from xhci_unmap_temp_buf | expand |
On Sat, Mar 06, 2021 at 08:06:44PM +0800, zhangkun4jr@163.com wrote: > From: Zhang Kun <zhangkun@cdjrlc.com> > > The value assigned to len by sg_pcopy_from_buffer() never used for > anything, so remove it. > > Signed-off-by: Zhang Kun <zhangkun@cdjrlc.com> > --- > drivers/usb/host/xhci.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c > index bd27bd670104..6ebda89d476c 100644 > --- a/drivers/usb/host/xhci.c > +++ b/drivers/usb/host/xhci.c > @@ -1335,7 +1335,6 @@ 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; > > @@ -1351,7 +1350,7 @@ 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, > + sg_pcopy_from_buffer(urb->sg, urb->num_sgs, > urb->transfer_buffer, > buf_len, > 0); SHouldn't this be checked instead of ignored? thanks, greg k-h
On 3/7/21 12:25 AM, Greg Kroah-Hartman wrote: > On Sat, Mar 06, 2021 at 08:06:44PM +0800, zhangkun4jr@163.com wrote: >> From: Zhang Kun <zhangkun@cdjrlc.com> >> >> The value assigned to len by sg_pcopy_from_buffer() never used for >> anything, so remove it. >> >> Signed-off-by: Zhang Kun <zhangkun@cdjrlc.com> >> --- >> drivers/usb/host/xhci.c | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c >> index bd27bd670104..6ebda89d476c 100644 >> --- a/drivers/usb/host/xhci.c >> +++ b/drivers/usb/host/xhci.c >> @@ -1335,7 +1335,6 @@ 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; >> >> @@ -1351,7 +1350,7 @@ 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, >> + sg_pcopy_from_buffer(urb->sg, urb->num_sgs, >> urb->transfer_buffer, >> buf_len, >> 0); > > SHouldn't this be checked instead of ignored? > Hi, Greg. Considering your tips I checked sg_pcopy_from_buffer(). it copys data from urb->transfer_buffer to urb->sg, and only returns 0 or the 'number of copied bytes', and seems to has no other exception branchs that need to be checked. So I think it should be ingnored. It may also be that I missed something, if that's the case, please correct me. Thanks, Zhang
On Sun, Mar 07, 2021 at 09:14:26AM +0800, Zhangkun wrote: > On 3/7/21 12:25 AM, Greg Kroah-Hartman wrote: > > On Sat, Mar 06, 2021 at 08:06:44PM +0800, zhangkun4jr@163.com wrote: > >> From: Zhang Kun <zhangkun@cdjrlc.com> > >> > >> The value assigned to len by sg_pcopy_from_buffer() never used for > >> anything, so remove it. > >> > >> Signed-off-by: Zhang Kun <zhangkun@cdjrlc.com> > >> --- > >> drivers/usb/host/xhci.c | 3 +-- > >> 1 file changed, 1 insertion(+), 2 deletions(-) > >> > >> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c > >> index bd27bd670104..6ebda89d476c 100644 > >> --- a/drivers/usb/host/xhci.c > >> +++ b/drivers/usb/host/xhci.c > >> @@ -1335,7 +1335,6 @@ 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; > >> > >> @@ -1351,7 +1350,7 @@ 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, > >> + sg_pcopy_from_buffer(urb->sg, urb->num_sgs, > >> urb->transfer_buffer, > >> buf_len, > >> 0); > > > > SHouldn't this be checked instead of ignored? > > > > Hi, Greg. > Considering your tips I checked sg_pcopy_from_buffer(). it copys data > from urb->transfer_buffer to urb->sg, and only returns 0 or the > 'number of copied bytes', and seems to has no other exception branchs > that need to be checked. So I think it should be ingnored. Why should you not check that the number of bytes was copied properly? thanks, greg k-h
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index bd27bd670104..6ebda89d476c 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -1335,7 +1335,6 @@ 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; @@ -1351,7 +1350,7 @@ 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, + sg_pcopy_from_buffer(urb->sg, urb->num_sgs, urb->transfer_buffer, buf_len, 0);