| Message ID | 1463530410-12772-1-git-send-email-xypron.glpk@gmx.de |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On 16-05-18 02:13:30, Heinrich Schuchardt wrote: > (!count || count < 4) is always true. > So let's remove the coding which is dead at least since 2005. You may want to reconsider the above statement. Just assume that 'count' is typically between 56 and 1514 bytes. Petko > Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> > --- > drivers/net/usb/pegasus.c | 53 ----------------------------------------------- > 1 file changed, 53 deletions(-) > > diff --git a/drivers/net/usb/pegasus.c b/drivers/net/usb/pegasus.c > index 36cd7f0..1903d2e 100644 > --- a/drivers/net/usb/pegasus.c > +++ b/drivers/net/usb/pegasus.c > @@ -470,61 +470,8 @@ static void read_bulk_callback(struct urb *urb) > return; > default: > netif_dbg(pegasus, rx_err, net, "RX status %d\n", status); > - goto goon; > } > > - if (!count || count < 4) > - goto goon; > - > - rx_status = buf[count - 2]; > - if (rx_status & 0x1e) { > - netif_dbg(pegasus, rx_err, net, > - "RX packet error %x\n", rx_status); > - pegasus->stats.rx_errors++; > - if (rx_status & 0x06) /* long or runt */ > - pegasus->stats.rx_length_errors++; > - if (rx_status & 0x08) > - pegasus->stats.rx_crc_errors++; > - if (rx_status & 0x10) /* extra bits */ > - pegasus->stats.rx_frame_errors++; > - goto goon; > - } > - if (pegasus->chip == 0x8513) { > - pkt_len = le32_to_cpu(*(__le32 *)urb->transfer_buffer); > - pkt_len &= 0x0fff; > - pegasus->rx_skb->data += 2; > - } else { > - pkt_len = buf[count - 3] << 8; > - pkt_len += buf[count - 4]; > - pkt_len &= 0xfff; > - pkt_len -= 4; > - } > - > - /* > - * If the packet is unreasonably long, quietly drop it rather than > - * kernel panicing by calling skb_put. > - */ > - if (pkt_len > PEGASUS_MTU) > - goto goon; > - > - /* > - * at this point we are sure pegasus->rx_skb != NULL > - * so we go ahead and pass up the packet. > - */ > - skb_put(pegasus->rx_skb, pkt_len); > - pegasus->rx_skb->protocol = eth_type_trans(pegasus->rx_skb, net); > - netif_rx(pegasus->rx_skb); > - pegasus->stats.rx_packets++; > - pegasus->stats.rx_bytes += pkt_len; > - > - if (pegasus->flags & PEGASUS_UNPLUG) > - return; > - > - pegasus->rx_skb = __netdev_alloc_skb_ip_align(pegasus->net, PEGASUS_MTU, > - GFP_ATOMIC); > - > - if (pegasus->rx_skb == NULL) > - goto tl_sched; > goon: > usb_fill_bulk_urb(pegasus->rx_urb, pegasus->usb, > usb_rcvbulkpipe(pegasus->usb, 1), > -- > 2.1.4 > >
On Wed, May 18, 2016 at 02:13:30AM +0200, Heinrich Schuchardt wrote: > (!count || count < 4) is always true. Even if count >= 4 ? Guenter > So let's remove the coding which is dead at least since 2005. > > Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> > > --- > drivers/net/usb/pegasus.c | 53 ----------------------------------------------- > 1 file changed, 53 deletions(-) > > diff --git a/drivers/net/usb/pegasus.c b/drivers/net/usb/pegasus.c > index 36cd7f0..1903d2e 100644 > --- a/drivers/net/usb/pegasus.c > +++ b/drivers/net/usb/pegasus.c > @@ -470,61 +470,8 @@ static void read_bulk_callback(struct urb *urb) > return; > default: > netif_dbg(pegasus, rx_err, net, "RX status %d\n", status); > - goto goon; > } > > - if (!count || count < 4) > - goto goon; > - > - rx_status = buf[count - 2]; > - if (rx_status & 0x1e) { > - netif_dbg(pegasus, rx_err, net, > - "RX packet error %x\n", rx_status); > - pegasus->stats.rx_errors++; > - if (rx_status & 0x06) /* long or runt */ > - pegasus->stats.rx_length_errors++; > - if (rx_status & 0x08) > - pegasus->stats.rx_crc_errors++; > - if (rx_status & 0x10) /* extra bits */ > - pegasus->stats.rx_frame_errors++; > - goto goon; > - } > - if (pegasus->chip == 0x8513) { > - pkt_len = le32_to_cpu(*(__le32 *)urb->transfer_buffer); > - pkt_len &= 0x0fff; > - pegasus->rx_skb->data += 2; > - } else { > - pkt_len = buf[count - 3] << 8; > - pkt_len += buf[count - 4]; > - pkt_len &= 0xfff; > - pkt_len -= 4; > - } > - > - /* > - * If the packet is unreasonably long, quietly drop it rather than > - * kernel panicing by calling skb_put. > - */ > - if (pkt_len > PEGASUS_MTU) > - goto goon; > - > - /* > - * at this point we are sure pegasus->rx_skb != NULL > - * so we go ahead and pass up the packet. > - */ > - skb_put(pegasus->rx_skb, pkt_len); > - pegasus->rx_skb->protocol = eth_type_trans(pegasus->rx_skb, net); > - netif_rx(pegasus->rx_skb); > - pegasus->stats.rx_packets++; > - pegasus->stats.rx_bytes += pkt_len; > - > - if (pegasus->flags & PEGASUS_UNPLUG) > - return; > - > - pegasus->rx_skb = __netdev_alloc_skb_ip_align(pegasus->net, PEGASUS_MTU, > - GFP_ATOMIC); > - > - if (pegasus->rx_skb == NULL) > - goto tl_sched; > goon: > usb_fill_bulk_urb(pegasus->rx_urb, pegasus->usb, > usb_rcvbulkpipe(pegasus->usb, 1),
On Tue, 2016-05-17 at 23:30 -0700, Guenter Roeck wrote: > On Wed, May 18, 2016 at 02:13:30AM +0200, Heinrich Schuchardt wrote: > > (!count || count < 4) is always true. > > Even if count >= 4 ? The check for !count is redundant, though. Gcc, however, will surely simplify the expression. Regards Oliver
On 16-05-18 09:15:40, Oliver Neukum wrote: > On Tue, 2016-05-17 at 23:30 -0700, Guenter Roeck wrote: > > On Wed, May 18, 2016 at 02:13:30AM +0200, Heinrich Schuchardt wrote: > > > (!count || count < 4) is always true. > > > > Even if count >= 4 ? > > The check for !count is redundant, though. Gcc, however, > will surely simplify the expression. Yep, gcc-6 generates this code: ... cmp $0x3,%edx jle b9 <read_bulk_callback+0x69> ... Which does not invalidate your statement that "!count" is redundant. :) Petko
From: Heinrich Schuchardt <xypron.glpk@gmx.de> Date: Wed, 18 May 2016 02:13:30 +0200 > (!count || count < 4) is always true. > So let's remove the coding which is dead at least since 2005. > > Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Applied.
On 16-05-19 11:35:42, David Miller wrote: > From: Heinrich Schuchardt <xypron.glpk@gmx.de> > Date: Wed, 18 May 2016 02:13:30 +0200 > > > (!count || count < 4) is always true. > > So let's remove the coding which is dead at least since 2005. > > > > Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> > > Applied. David, the patch you applied is broken. It seems that you didn't follow the discussion from the past couple of days. Please revert it. Petko
From: Petko Manolov <petkan@mip-labs.com> Date: Fri, 20 May 2016 10:33:47 +0300 > On 16-05-19 11:35:42, David Miller wrote: >> From: Heinrich Schuchardt <xypron.glpk@gmx.de> >> Date: Wed, 18 May 2016 02:13:30 +0200 >> >> > (!count || count < 4) is always true. >> > So let's remove the coding which is dead at least since 2005. >> > >> > Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> >> >> Applied. > > David, the patch you applied is broken. It seems that you didn't follow the > discussion from the past couple of days. Please revert it. I did.
diff --git a/drivers/net/usb/pegasus.c b/drivers/net/usb/pegasus.c index 36cd7f0..1903d2e 100644 --- a/drivers/net/usb/pegasus.c +++ b/drivers/net/usb/pegasus.c @@ -470,61 +470,8 @@ static void read_bulk_callback(struct urb *urb) return; default: netif_dbg(pegasus, rx_err, net, "RX status %d\n", status); - goto goon; } - if (!count || count < 4) - goto goon; - - rx_status = buf[count - 2]; - if (rx_status & 0x1e) { - netif_dbg(pegasus, rx_err, net, - "RX packet error %x\n", rx_status); - pegasus->stats.rx_errors++; - if (rx_status & 0x06) /* long or runt */ - pegasus->stats.rx_length_errors++; - if (rx_status & 0x08) - pegasus->stats.rx_crc_errors++; - if (rx_status & 0x10) /* extra bits */ - pegasus->stats.rx_frame_errors++; - goto goon; - } - if (pegasus->chip == 0x8513) { - pkt_len = le32_to_cpu(*(__le32 *)urb->transfer_buffer); - pkt_len &= 0x0fff; - pegasus->rx_skb->data += 2; - } else { - pkt_len = buf[count - 3] << 8; - pkt_len += buf[count - 4]; - pkt_len &= 0xfff; - pkt_len -= 4; - } - - /* - * If the packet is unreasonably long, quietly drop it rather than - * kernel panicing by calling skb_put. - */ - if (pkt_len > PEGASUS_MTU) - goto goon; - - /* - * at this point we are sure pegasus->rx_skb != NULL - * so we go ahead and pass up the packet. - */ - skb_put(pegasus->rx_skb, pkt_len); - pegasus->rx_skb->protocol = eth_type_trans(pegasus->rx_skb, net); - netif_rx(pegasus->rx_skb); - pegasus->stats.rx_packets++; - pegasus->stats.rx_bytes += pkt_len; - - if (pegasus->flags & PEGASUS_UNPLUG) - return; - - pegasus->rx_skb = __netdev_alloc_skb_ip_align(pegasus->net, PEGASUS_MTU, - GFP_ATOMIC); - - if (pegasus->rx_skb == NULL) - goto tl_sched; goon: usb_fill_bulk_urb(pegasus->rx_urb, pegasus->usb, usb_rcvbulkpipe(pegasus->usb, 1),
(!count || count < 4) is always true. So let's remove the coding which is dead at least since 2005. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> --- drivers/net/usb/pegasus.c | 53 ----------------------------------------------- 1 file changed, 53 deletions(-)