* [PATCH 1/1] net: pegasus: remove dead coding
@ 2016-05-18 0:13 ` Heinrich Schuchardt
0 siblings, 0 replies; 12+ messages in thread
From: Heinrich Schuchardt @ 2016-05-18 0:13 UTC (permalink / raw)
To: Petko Manolov
Cc: linux-usb-u79uwXL29TY76Z2rM5mHXA, netdev-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA, Heinrich Schuchardt
(!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-Mmb7MZpHnFY@public.gmane.org>
---
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);
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH 1/1] net: pegasus: remove dead coding
2016-05-18 0:13 ` Heinrich Schuchardt
(?)
@ 2016-05-18 6:25 ` Petko Manolov
-1 siblings, 0 replies; 12+ messages in thread
From: Petko Manolov @ 2016-05-18 6:25 UTC (permalink / raw)
To: Heinrich Schuchardt; +Cc: Petko Manolov, linux-usb, netdev, linux-kernel
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
>
>
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [1/1] net: pegasus: remove dead coding
2016-05-18 0:13 ` Heinrich Schuchardt
(?)
(?)
@ 2016-05-18 6:30 ` Guenter Roeck
2016-05-18 7:15 ` Oliver Neukum
-1 siblings, 1 reply; 12+ messages in thread
From: Guenter Roeck @ 2016-05-18 6:30 UTC (permalink / raw)
To: Heinrich Schuchardt; +Cc: Petko Manolov, linux-usb, netdev, linux-kernel
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),
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [1/1] net: pegasus: remove dead coding
2016-05-18 6:30 ` [1/1] " Guenter Roeck
@ 2016-05-18 7:15 ` Oliver Neukum
2016-05-18 7:50 ` Petko Manolov
2016-05-18 18:40 ` [PATCH 1/1] net: pegasus: simplify logical constraint Heinrich Schuchardt
0 siblings, 2 replies; 12+ messages in thread
From: Oliver Neukum @ 2016-05-18 7:15 UTC (permalink / raw)
To: Guenter Roeck
Cc: Heinrich Schuchardt, Petko Manolov, linux-kernel, linux-usb, netdev
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
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [1/1] net: pegasus: remove dead coding
2016-05-18 7:15 ` Oliver Neukum
@ 2016-05-18 7:50 ` Petko Manolov
2016-05-18 18:40 ` [PATCH 1/1] net: pegasus: simplify logical constraint Heinrich Schuchardt
1 sibling, 0 replies; 12+ messages in thread
From: Petko Manolov @ 2016-05-18 7:50 UTC (permalink / raw)
To: Oliver Neukum
Cc: Guenter Roeck, Heinrich Schuchardt, Petko Manolov, linux-kernel,
linux-usb, netdev
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
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 1/1] net: pegasus: simplify logical constraint
2016-05-18 7:15 ` Oliver Neukum
2016-05-18 7:50 ` Petko Manolov
@ 2016-05-18 18:40 ` Heinrich Schuchardt
2016-05-19 5:57 ` Petko Manolov
2016-05-23 20:49 ` David Miller
1 sibling, 2 replies; 12+ messages in thread
From: Heinrich Schuchardt @ 2016-05-18 18:40 UTC (permalink / raw)
To: Petko Manolov, Petko Manolov
Cc: Oliver Neukum, Guenter Roeck, linux-usb, netdev, linux-kernel,
Heinrich Schuchardt
If !count is true, count < 4 is also true.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
drivers/net/usb/pegasus.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/usb/pegasus.c b/drivers/net/usb/pegasus.c
index 36cd7f0..9bbe0161 100644
--- a/drivers/net/usb/pegasus.c
+++ b/drivers/net/usb/pegasus.c
@@ -473,7 +473,7 @@ static void read_bulk_callback(struct urb *urb)
goto goon;
}
- if (!count || count < 4)
+ if (count < 4)
goto goon;
rx_status = buf[count - 2];
--
2.1.4
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH 1/1] net: pegasus: simplify logical constraint
2016-05-18 18:40 ` [PATCH 1/1] net: pegasus: simplify logical constraint Heinrich Schuchardt
@ 2016-05-19 5:57 ` Petko Manolov
2016-05-23 20:49 ` David Miller
1 sibling, 0 replies; 12+ messages in thread
From: Petko Manolov @ 2016-05-19 5:57 UTC (permalink / raw)
To: Heinrich Schuchardt
Cc: Petko Manolov, Oliver Neukum, Guenter Roeck, linux-usb, netdev,
linux-kernel
On 16-05-18 20:40:51, Heinrich Schuchardt wrote:
> If !count is true, count < 4 is also true.
Yep, you're right. However, gcc optimizes away the first condition. What you
really got me to think about is whether 4 is the right number. I guess i shall
refer to the HW documentation.
Petko
> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
> ---
> drivers/net/usb/pegasus.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/usb/pegasus.c b/drivers/net/usb/pegasus.c
> index 36cd7f0..9bbe0161 100644
> --- a/drivers/net/usb/pegasus.c
> +++ b/drivers/net/usb/pegasus.c
> @@ -473,7 +473,7 @@ static void read_bulk_callback(struct urb *urb)
> goto goon;
> }
>
> - if (!count || count < 4)
> + if (count < 4)
> goto goon;
>
> rx_status = buf[count - 2];
> --
> 2.1.4
>
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 1/1] net: pegasus: simplify logical constraint
2016-05-18 18:40 ` [PATCH 1/1] net: pegasus: simplify logical constraint Heinrich Schuchardt
2016-05-19 5:57 ` Petko Manolov
@ 2016-05-23 20:49 ` David Miller
1 sibling, 0 replies; 12+ messages in thread
From: David Miller @ 2016-05-23 20:49 UTC (permalink / raw)
To: xypron.glpk
Cc: petkan, petkan, oneukum, linux, linux-usb, netdev, linux-kernel
From: Heinrich Schuchardt <xypron.glpk@gmx.de>
Date: Wed, 18 May 2016 20:40:51 +0200
> If !count is true, count < 4 is also true.
>
> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Applied.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 1/1] net: pegasus: remove dead coding
2016-05-18 0:13 ` Heinrich Schuchardt
` (2 preceding siblings ...)
(?)
@ 2016-05-19 18:35 ` David Miller
2016-05-20 7:33 ` Petko Manolov
-1 siblings, 1 reply; 12+ messages in thread
From: David Miller @ 2016-05-19 18:35 UTC (permalink / raw)
To: xypron.glpk; +Cc: petkan, linux-usb, netdev, linux-kernel
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.
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH 1/1] net: pegasus: remove dead coding
2016-05-19 18:35 ` [PATCH 1/1] net: pegasus: remove dead coding David Miller
@ 2016-05-20 7:33 ` Petko Manolov
2016-05-20 16:38 ` David Miller
0 siblings, 1 reply; 12+ messages in thread
From: Petko Manolov @ 2016-05-20 7:33 UTC (permalink / raw)
To: David Miller; +Cc: xypron.glpk, petkan, linux-usb, netdev, linux-kernel
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
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 1/1] net: pegasus: remove dead coding
2016-05-20 7:33 ` Petko Manolov
@ 2016-05-20 16:38 ` David Miller
0 siblings, 0 replies; 12+ messages in thread
From: David Miller @ 2016-05-20 16:38 UTC (permalink / raw)
To: petkan; +Cc: xypron.glpk, petkan, linux-usb, netdev, linux-kernel
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.
^ permalink raw reply [flat|nested] 12+ messages in thread