* Re: [PATCH net v1] lan743x: fix ethernet frame cutoff issue
2021-04-09 0:39 [PATCH net v1] lan743x: fix ethernet frame cutoff issue Sven Van Asbroeck
@ 2021-04-09 1:02 ` Andrew Lunn
2021-04-09 1:13 ` Sven Van Asbroeck
2021-04-09 14:12 ` George McCollister
` (2 subsequent siblings)
3 siblings, 1 reply; 10+ messages in thread
From: Andrew Lunn @ 2021-04-09 1:02 UTC (permalink / raw)
To: Sven Van Asbroeck
Cc: Bryan Whitehead, David S Miller, Jakub Kicinski,
George McCollister, Heiner Kallweit, UNGLinuxDriver, netdev,
linux-kernel
Hi Sven
> Many thanks to Heiner Kallweit for suggesting this solution.
Adding a Suggested-by: would be good. And it might sometime help
Johnathan Corbet extract some interesting statistics from the commit
messages if everybody uses the same format.
Andrew
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH net v1] lan743x: fix ethernet frame cutoff issue
2021-04-09 1:02 ` Andrew Lunn
@ 2021-04-09 1:13 ` Sven Van Asbroeck
0 siblings, 0 replies; 10+ messages in thread
From: Sven Van Asbroeck @ 2021-04-09 1:13 UTC (permalink / raw)
To: Andrew Lunn
Cc: Bryan Whitehead, David S Miller, Jakub Kicinski,
George McCollister, Heiner Kallweit,
Microchip Linux Driver Support, netdev,
Linux Kernel Mailing List
Hi Andrew,
On Thu, Apr 8, 2021 at 9:02 PM Andrew Lunn <andrew@lunn.ch> wrote:
>
> Adding a Suggested-by: would be good. And it might sometime help
> Johnathan Corbet extract some interesting statistics from the commit
> messages if everybody uses the same format.
Thank you for the suggestion. I'll definitely use that in the future.
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH net v1] lan743x: fix ethernet frame cutoff issue
2021-04-09 0:39 [PATCH net v1] lan743x: fix ethernet frame cutoff issue Sven Van Asbroeck
2021-04-09 1:02 ` Andrew Lunn
@ 2021-04-09 14:12 ` George McCollister
2021-04-09 14:38 ` Sven Van Asbroeck
2021-04-09 20:00 ` patchwork-bot+netdevbpf
2021-04-14 12:53 ` Julian Wiedmann
3 siblings, 1 reply; 10+ messages in thread
From: George McCollister @ 2021-04-09 14:12 UTC (permalink / raw)
To: Sven Van Asbroeck
Cc: Bryan Whitehead, David S Miller, Jakub Kicinski, Heiner Kallweit,
Andrew Lunn, Microchip Linux Driver Support, netdev, open list
On Thu, Apr 8, 2021 at 7:39 PM Sven Van Asbroeck <thesven73@gmail.com> wrote:
>
> From: Sven Van Asbroeck <thesven73@gmail.com>
>
> The ethernet frame length is calculated incorrectly. Depending on
> the value of RX_HEAD_PADDING, this may result in ethernet frames
> that are too short (cut off at the end), or too long (garbage added
> to the end).
>
> Fix by calculating the ethernet frame length correctly. For added
> clarity, use the ETH_FCS_LEN constant in the calculation.
>
> Many thanks to Heiner Kallweit for suggesting this solution.
>
> Fixes: 3e21a10fdea3 ("lan743x: trim all 4 bytes of the FCS; not just 2")
> Link: https://lore.kernel.org/lkml/20210408172353.21143-1-TheSven73@gmail.com/
> Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
I'm glad everyone was able to work together to get this fixed properly
without any figure pointing or mud slinging! Kudos everyone.
Reviewed-by: George McCollister <george.mccollister@gmail.com>
Tested-By: George McCollister <george.mccollister@gmail.com>
> ---
>
> Tree: git://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git # 864db232dc70
>
> To: Bryan Whitehead <bryan.whitehead@microchip.com>
> To: "David S. Miller" <davem@davemloft.net>
> To: Jakub Kicinski <kuba@kernel.org>
> To: George McCollister <george.mccollister@gmail.com>
> Cc: Heiner Kallweit <hkallweit1@gmail.com>
> Cc: Andrew Lunn <andrew@lunn.ch>
> Cc: UNGLinuxDriver@microchip.com
> Cc: netdev@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
>
> drivers/net/ethernet/microchip/lan743x_main.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
> index 1c3e204d727c..7b6794aa8ea9 100644
> --- a/drivers/net/ethernet/microchip/lan743x_main.c
> +++ b/drivers/net/ethernet/microchip/lan743x_main.c
> @@ -885,8 +885,8 @@ static int lan743x_mac_set_mtu(struct lan743x_adapter *adapter, int new_mtu)
> }
>
> mac_rx &= ~(MAC_RX_MAX_SIZE_MASK_);
> - mac_rx |= (((new_mtu + ETH_HLEN + 4) << MAC_RX_MAX_SIZE_SHIFT_) &
> - MAC_RX_MAX_SIZE_MASK_);
> + mac_rx |= (((new_mtu + ETH_HLEN + ETH_FCS_LEN)
> + << MAC_RX_MAX_SIZE_SHIFT_) & MAC_RX_MAX_SIZE_MASK_);
> lan743x_csr_write(adapter, MAC_RX, mac_rx);
>
> if (enabled) {
> @@ -1944,7 +1944,7 @@ static int lan743x_rx_init_ring_element(struct lan743x_rx *rx, int index)
> struct sk_buff *skb;
> dma_addr_t dma_ptr;
>
> - buffer_length = netdev->mtu + ETH_HLEN + 4 + RX_HEAD_PADDING;
> + buffer_length = netdev->mtu + ETH_HLEN + ETH_FCS_LEN + RX_HEAD_PADDING;
>
> descriptor = &rx->ring_cpu_ptr[index];
> buffer_info = &rx->buffer_info[index];
> @@ -2040,7 +2040,7 @@ lan743x_rx_trim_skb(struct sk_buff *skb, int frame_length)
> dev_kfree_skb_irq(skb);
> return NULL;
> }
> - frame_length = max_t(int, 0, frame_length - RX_HEAD_PADDING - 4);
> + frame_length = max_t(int, 0, frame_length - ETH_FCS_LEN);
> if (skb->len > frame_length) {
> skb->tail -= skb->len - frame_length;
> skb->len = frame_length;
> --
> 2.17.1
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH net v1] lan743x: fix ethernet frame cutoff issue
2021-04-09 14:12 ` George McCollister
@ 2021-04-09 14:38 ` Sven Van Asbroeck
0 siblings, 0 replies; 10+ messages in thread
From: Sven Van Asbroeck @ 2021-04-09 14:38 UTC (permalink / raw)
To: George McCollister
Cc: Bryan Whitehead, David S Miller, Jakub Kicinski, Heiner Kallweit,
Andrew Lunn, Microchip Linux Driver Support, netdev, open list
Hi George,
On Fri, Apr 9, 2021 at 10:12 AM George McCollister
<george.mccollister@gmail.com> wrote:
>
> I'm glad everyone was able to work together to get this fixed properly
> without any figure pointing or mud slinging! Kudos everyone.
Same, this is what the kernel community is supposed to be all about.
And thank you for testing+reviewing. And for not freaking out too much
when I lobbed that revert patch in your general direction :-]
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH net v1] lan743x: fix ethernet frame cutoff issue
2021-04-09 0:39 [PATCH net v1] lan743x: fix ethernet frame cutoff issue Sven Van Asbroeck
2021-04-09 1:02 ` Andrew Lunn
2021-04-09 14:12 ` George McCollister
@ 2021-04-09 20:00 ` patchwork-bot+netdevbpf
2021-04-14 12:53 ` Julian Wiedmann
3 siblings, 0 replies; 10+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-04-09 20:00 UTC (permalink / raw)
To: Sven Van Asbroeck
Cc: bryan.whitehead, davem, kuba, george.mccollister, hkallweit1,
andrew, UNGLinuxDriver, netdev, linux-kernel
Hello:
This patch was applied to netdev/net.git (refs/heads/master):
On Thu, 8 Apr 2021 20:39:04 -0400 you wrote:
> From: Sven Van Asbroeck <thesven73@gmail.com>
>
> The ethernet frame length is calculated incorrectly. Depending on
> the value of RX_HEAD_PADDING, this may result in ethernet frames
> that are too short (cut off at the end), or too long (garbage added
> to the end).
>
> [...]
Here is the summary with links:
- [net,v1] lan743x: fix ethernet frame cutoff issue
https://git.kernel.org/netdev/net/c/3bc41d6d2721
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH net v1] lan743x: fix ethernet frame cutoff issue
2021-04-09 0:39 [PATCH net v1] lan743x: fix ethernet frame cutoff issue Sven Van Asbroeck
` (2 preceding siblings ...)
2021-04-09 20:00 ` patchwork-bot+netdevbpf
@ 2021-04-14 12:53 ` Julian Wiedmann
2021-04-14 13:19 ` Sven Van Asbroeck
3 siblings, 1 reply; 10+ messages in thread
From: Julian Wiedmann @ 2021-04-14 12:53 UTC (permalink / raw)
To: Sven Van Asbroeck, Bryan Whitehead, David S Miller,
Jakub Kicinski, George McCollister
Cc: Heiner Kallweit, Andrew Lunn, UNGLinuxDriver, netdev, linux-kernel
On 09.04.21 02:39, Sven Van Asbroeck wrote:
> From: Sven Van Asbroeck <thesven73@gmail.com>
>
> The ethernet frame length is calculated incorrectly. Depending on
> the value of RX_HEAD_PADDING, this may result in ethernet frames
> that are too short (cut off at the end), or too long (garbage added
> to the end).
>
> Fix by calculating the ethernet frame length correctly. For added
> clarity, use the ETH_FCS_LEN constant in the calculation.
>
> Many thanks to Heiner Kallweit for suggesting this solution.
>
> Fixes: 3e21a10fdea3 ("lan743x: trim all 4 bytes of the FCS; not just 2")
> Link: https://lore.kernel.org/lkml/20210408172353.21143-1-TheSven73@gmail.com/
> Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
> ---
>
> Tree: git://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git # 864db232dc70
>
> To: Bryan Whitehead <bryan.whitehead@microchip.com>
> To: "David S. Miller" <davem@davemloft.net>
> To: Jakub Kicinski <kuba@kernel.org>
> To: George McCollister <george.mccollister@gmail.com>
> Cc: Heiner Kallweit <hkallweit1@gmail.com>
> Cc: Andrew Lunn <andrew@lunn.ch>
> Cc: UNGLinuxDriver@microchip.com
> Cc: netdev@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
>
> drivers/net/ethernet/microchip/lan743x_main.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
> index 1c3e204d727c..7b6794aa8ea9 100644
> --- a/drivers/net/ethernet/microchip/lan743x_main.c
> +++ b/drivers/net/ethernet/microchip/lan743x_main.c
> @@ -885,8 +885,8 @@ static int lan743x_mac_set_mtu(struct lan743x_adapter *adapter, int new_mtu)
> }
>
> mac_rx &= ~(MAC_RX_MAX_SIZE_MASK_);
> - mac_rx |= (((new_mtu + ETH_HLEN + 4) << MAC_RX_MAX_SIZE_SHIFT_) &
> - MAC_RX_MAX_SIZE_MASK_);
> + mac_rx |= (((new_mtu + ETH_HLEN + ETH_FCS_LEN)
> + << MAC_RX_MAX_SIZE_SHIFT_) & MAC_RX_MAX_SIZE_MASK_);
> lan743x_csr_write(adapter, MAC_RX, mac_rx);
>
> if (enabled) {
> @@ -1944,7 +1944,7 @@ static int lan743x_rx_init_ring_element(struct lan743x_rx *rx, int index)
> struct sk_buff *skb;
> dma_addr_t dma_ptr;
>
> - buffer_length = netdev->mtu + ETH_HLEN + 4 + RX_HEAD_PADDING;
> + buffer_length = netdev->mtu + ETH_HLEN + ETH_FCS_LEN + RX_HEAD_PADDING;
>
On a cursory glance, using __netdev_alloc_skb_ip_align() here should
allow you to get rid of all the RX_HEAD_PADDING gymnastics.
And also avoid the need for setting RX_CFG_B_RX_PAD_2_, as the
NET_IP_ALIGN part would no longer get dma-mapped.
> descriptor = &rx->ring_cpu_ptr[index];
> buffer_info = &rx->buffer_info[index];
> @@ -2040,7 +2040,7 @@ lan743x_rx_trim_skb(struct sk_buff *skb, int frame_length)
> dev_kfree_skb_irq(skb);
> return NULL;
> }
> - frame_length = max_t(int, 0, frame_length - RX_HEAD_PADDING - 4);
> + frame_length = max_t(int, 0, frame_length - ETH_FCS_LEN);
> if (skb->len > frame_length) {
> skb->tail -= skb->len - frame_length;
> skb->len = frame_length;
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH net v1] lan743x: fix ethernet frame cutoff issue
2021-04-14 12:53 ` Julian Wiedmann
@ 2021-04-14 13:19 ` Sven Van Asbroeck
2021-04-14 13:33 ` Julian Wiedmann
0 siblings, 1 reply; 10+ messages in thread
From: Sven Van Asbroeck @ 2021-04-14 13:19 UTC (permalink / raw)
To: Julian Wiedmann
Cc: Bryan Whitehead, David S Miller, Jakub Kicinski,
George McCollister, Heiner Kallweit, Andrew Lunn,
Microchip Linux Driver Support, netdev,
Linux Kernel Mailing List
Hi Julian,
On Wed, Apr 14, 2021 at 8:53 AM Julian Wiedmann <jwi@linux.ibm.com> wrote:
>
> On a cursory glance, using __netdev_alloc_skb_ip_align() here should
> allow you to get rid of all the RX_HEAD_PADDING gymnastics.
>
> And also avoid the need for setting RX_CFG_B_RX_PAD_2_, as the
> NET_IP_ALIGN part would no longer get dma-mapped.
That's an excellent suggestion, and I'll definitely keep that in mind
for the future.
In this case, I'm not sure if it could work. This NIC has multi-buffer
frames. The dma-ed skbs represent frame fragments. A flag in the
descriptor ring indicates if an skb is "first". If first, we can
reserve the padding. Otherwise, we cannot. because that would corrupt
a fragment in the middle. At the time of skb allocation, we do not
know whether that skb will be "first".
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/microchip/lan743x_main.c?h=v5.12-rc7#n2125
Maybe I'm missing a trick here? Feel free to suggest improvements,
it's always much appreciated.
Sven
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH net v1] lan743x: fix ethernet frame cutoff issue
2021-04-14 13:19 ` Sven Van Asbroeck
@ 2021-04-14 13:33 ` Julian Wiedmann
2021-04-14 13:40 ` Sven Van Asbroeck
0 siblings, 1 reply; 10+ messages in thread
From: Julian Wiedmann @ 2021-04-14 13:33 UTC (permalink / raw)
To: Sven Van Asbroeck
Cc: Bryan Whitehead, David S Miller, Jakub Kicinski,
George McCollister, Heiner Kallweit, Andrew Lunn,
Microchip Linux Driver Support, netdev,
Linux Kernel Mailing List
On 14.04.21 15:19, Sven Van Asbroeck wrote:
> Hi Julian,
>
> On Wed, Apr 14, 2021 at 8:53 AM Julian Wiedmann <jwi@linux.ibm.com> wrote:
>>
>> On a cursory glance, using __netdev_alloc_skb_ip_align() here should
>> allow you to get rid of all the RX_HEAD_PADDING gymnastics.
>>
>> And also avoid the need for setting RX_CFG_B_RX_PAD_2_, as the
>> NET_IP_ALIGN part would no longer get dma-mapped.
>
> That's an excellent suggestion, and I'll definitely keep that in mind
> for the future.
>
> In this case, I'm not sure if it could work. This NIC has multi-buffer
> frames. The dma-ed skbs represent frame fragments. A flag in the
> descriptor ring indicates if an skb is "first". If first, we can
> reserve the padding. Otherwise, we cannot. because that would corrupt
> a fragment in the middle. At the time of skb allocation, we do not
> know whether that skb will be "first".
>
__netdev_alloc_skb_ip_align() already reserves the NET_IP_ALIGN part.
So when the NIC stores into the dma-mapped skb->data parts, each
fragment will automatically have the required alignment - even when
you only care about the first fragment's alignment.
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/microchip/lan743x_main.c?h=v5.12-rc7#n2125
>
> Maybe I'm missing a trick here? Feel free to suggest improvements,
> it's always much appreciated.
>
> Sven
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH net v1] lan743x: fix ethernet frame cutoff issue
2021-04-14 13:33 ` Julian Wiedmann
@ 2021-04-14 13:40 ` Sven Van Asbroeck
0 siblings, 0 replies; 10+ messages in thread
From: Sven Van Asbroeck @ 2021-04-14 13:40 UTC (permalink / raw)
To: Julian Wiedmann
Cc: Bryan Whitehead, David S Miller, Jakub Kicinski,
George McCollister, Heiner Kallweit, Andrew Lunn,
Microchip Linux Driver Support, netdev,
Linux Kernel Mailing List
Hi Julian,
On Wed, Apr 14, 2021 at 9:33 AM Julian Wiedmann <jwi@linux.ibm.com> wrote:
>
> __netdev_alloc_skb_ip_align() already reserves the NET_IP_ALIGN part.
> So when the NIC stores into the dma-mapped skb->data parts, each
> fragment will automatically have the required alignment - even when
> you only care about the first fragment's alignment.
>
That's really interesting! I'm going to try that out.
^ permalink raw reply [flat|nested] 10+ messages in thread