On 05/08/2020 12:29, Kurt Kanzenbach wrote:
On Wed Aug 05 2020, Russell King - ARM Linux admin wrote:
On Wed, Aug 05, 2020 at 01:04:31AM +0300, Grygorii Strashko wrote:
On 05/08/2020 00:44, Russell King - ARM Linux admin wrote:
On Wed, Aug 05, 2020 at 12:34:47AM +0300, Grygorii Strashko wrote:
On 05/08/2020 00:07, Russell King - ARM Linux admin wrote:
On Tue, Aug 04, 2020 at 11:56:12PM +0300, Grygorii Strashko wrote:
On 31/07/2020 13:06, Kurt Kanzenbach wrote:
On Thu Jul 30 2020, Petr Machata wrote:
Kurt Kanzenbach <k...@linutronix.de> writes:
@@ -107,6 +107,37 @@ unsigned int ptp_classify_raw(const struct sk_buff *skb)
}
EXPORT_SYMBOL_GPL(ptp_classify_raw);
+struct ptp_header *ptp_parse_header(struct sk_buff *skb, unsigned int type)
+{
+ u8 *data = skb_mac_header(skb);
+ u8 *ptr = data;
One of the "data" and "ptr" variables is superfluous.
Yeah. Can be shortened to u8 *ptr = skb_mac_header(skb);
Actually usage of skb_mac_header(skb) breaks CPTS RX time-stamping on
am571x platform PATCH 6.
The CPSW RX timestamp requested after full packet put in SKB, but
before calling eth_type_trans().
So, skb->data pints on Eth header, but skb_mac_header() return garbage.
Below diff fixes it for me.
However, that's likely to break everyone else.
For example, anyone calling this from the mii_timestamper rxtstamp()
method, the skb will have been classified with the MAC header pushed
and restored, so skb->data points at the network header.
Your change means that ptp_parse_header() expects the MAC header to
also be pushed.
Is it possible to adjust CPTS?
Looking at:
drivers/net/ethernet/ti/cpsw.c... yes.
drivers/net/ethernet/ti/cpsw_new.c... yes.
drivers/net/ethernet/ti/netcp_core.c... unclear.
If not, maybe cpts should remain unconverted - I don't see any reason
to provide a generic function for one user.
Could it be an option to pass "u8 *ptr" instead of "const struct sk_buff *skb"
as
input parameter to ptp_parse_header()?
It needs to read from the buffer, and in order to do that, it needs to
validate that the buffer contains sufficient data. So, at minimum it
needs to be a pointer and size of valid data.
I was thinking about suggesting that as a core function, with a wrapper
for the existing interface.
Then length can be added.
Actually, it needs more than that, because skb->data..skb->len already
may contain the eth header or may not.
Otherwise not only CPTS can't benefit from this new API, but also
drivers like oki-semi/pch_gbe/pch_gbe_main.c -> pch_ptp_match()
Again, this looks like it can be solved easily by swapping the position
of these two calls:
pch_rx_timestamp(adapter, skb);
skb->protocol = eth_type_trans(skb, netdev);
Sry, it will not be so "easily", because there is ptp_classify_raw() inside.
So every such case, will require rework and adding magic like this
__skb_push(skb, ETH_HLEN);
type = ptp_classify_raw(skb);
__skb_pull(skb, ETH_HLEN);
in Hot path.
or have to two have two APIs (name?).
ptp_parse_header1(struct sk_buff *skb, unsigned int type)
{
u8 *data = skb_mac_header(skb);
ptp_parse_header2(struct sk_buff *skb, unsigned int type)
{
u8 *data = skb->data;
everything else is the same.
Actually, I really don't think we want 99% of users doing:
hdr = ptp_parse_header(skb_mac_header(skb), skb->data, skb->len, type)
or
hdr = ptp_parse_header(skb_mac_header(skb), skb->data + skb->len, type);
because that is what it will take, and this is starting to look
really very horrid.
True.
So, I repeat my question again: can netcp_core.c be adjusted to
ensure that the skb mac header field is correctly set by calling
eth_type_trans() prior to calling the rx hooks? The other two
cpts cases look easy to change, and the oki-semi also looks the
same.
I think it's possible to adjust the netcp core. So, the time stamping is
done via
gbe_rxhook() -> gbe_rxtstamp() -> cpts_rx_timestamp()
The hooks are called in netcp_process_one_rx_packet(). So, moving
eth_type_trans() before executing the hooks should work. Only one hook
is registered.
What do you think about it?
I really do not want touch netcp, sry.
There are other internal code based on this even if there is only one hooks in
LKML now.
+ my comment above.
I'll try use skb_reset_mac_header(skb);
As spectrum does:
skb_reset_mac_header(skb);
mlxsw_sp1_ptp_got_packet(mlxsw_sp, skb, local_port, true);
if doesn't help PATCH 6 is to drop.
--
Best regards,
grygorii
