lkml.org 
[lkml]   [2023]   [Jan]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v4 1/3] dsa: marvell: Provide per device information about max frame size
On Fri, Jan 06, 2023 at 11:16:49AM +0100, Lukasz Majewski wrote:
> Different Marvell DSA switches support different size of max frame
> bytes to be sent. This value corresponds to the memory allocated
> in switch to store single frame.
>
> For example mv88e6185 supports max 1632 bytes, which is now in-driver
> standard value. On the other hand - mv88e6250 supports 2048 bytes.
> To be more interresting - devices supporting jumbo frames - use yet
> another value (10240 bytes)
>
> As this value is internal and may be different for each switch IC,
> new entry in struct mv88e6xxx_info has been added to store it.
>
> This commit doesn't change the code functionality - it just provides
> the max frame size value explicitly - up till now it has been
> assigned depending on the callback provided by the IC driver
> (e.g. .set_max_frame_size, .port_set_jumbo_size).
>
> Signed-off-by: Lukasz Majewski <lukma@denx.de>
>
> ---
> Changes for v2:
> - Define max_frame_size with default value of 1632 bytes,
> - Set proper value for the mv88e6250 switch SoC (linkstreet) family
>
> Changes for v3:
> - Add default value for 1632B of the max frame size (to avoid problems
> with not defined values)
>
> Changes for v4:
> - Rework the mv88e6xxx_get_max_mtu() by using per device defined
> max_frame_size value
>
> - Add WARN_ON_ONCE() when max_frame_size is not defined
>
> - Add description for the new 'max_frame_size' member of mv88e6xxx_info
> ---
> drivers/net/dsa/mv88e6xxx/chip.c | 41 ++++++++++++++++++++++++++++----
> drivers/net/dsa/mv88e6xxx/chip.h | 6 +++++
> 2 files changed, 42 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
> index 242b8b325504..fc6d98c4a029 100644
> --- a/drivers/net/dsa/mv88e6xxx/chip.c
> +++ b/drivers/net/dsa/mv88e6xxx/chip.c
> @@ -3545,11 +3545,10 @@ static int mv88e6xxx_get_max_mtu(struct dsa_switch *ds, int port)
> {
> struct mv88e6xxx_chip *chip = ds->priv;
>
> - if (chip->info->ops->port_set_jumbo_size)
> - return 10240 - VLAN_ETH_HLEN - EDSA_HLEN - ETH_FCS_LEN;
> - else if (chip->info->ops->set_max_frame_size)
> - return 1632 - VLAN_ETH_HLEN - EDSA_HLEN - ETH_FCS_LEN;
> - return 1522 - VLAN_ETH_HLEN - EDSA_HLEN - ETH_FCS_LEN;
> + WARN_ON_ONCE(!chip->info->max_frame_size);
> +
> + return chip->info->max_frame_size - VLAN_ETH_HLEN - EDSA_HLEN
> + - ETH_FCS_LEN;

VLAN_ETH_HLEN (18) + EDSA_HLEN (8) + ETH_FCS_LEN (4) = 30

> }
>
> static int mv88e6xxx_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
> @@ -4955,6 +4954,7 @@ static const struct mv88e6xxx_ops mv88e6250_ops = {
> .avb_ops = &mv88e6352_avb_ops,
> .ptp_ops = &mv88e6250_ptp_ops,
> .phylink_get_caps = mv88e6250_phylink_get_caps,
> + .set_max_frame_size = mv88e6185_g1_set_max_frame_size,
> };
>
> static const struct mv88e6xxx_ops mv88e6290_ops = {
> @@ -5543,6 +5543,7 @@ static const struct mv88e6xxx_info mv88e6xxx_table[] = {
> .num_internal_phys = 5,
> .max_vid = 4095,
> .max_sid = 63,
> + .max_frame_size = 1522,

1522 - 30 = 1492.

I don't believe that there are switches which don't support the standard
MTU of 1500 ?!

> .port_base_addr = 0x10,
> .phy_base_addr = 0x0,
> .global1_addr = 0x1b,

Note that I see this behavior isn't new. But I've simulated it, and it
will produce the following messages on probe:

[ 7.425752] mscc_felix 0000:00:00.5 swp0 (uninitialized): PHY [0000:00:00.3:10] driver [Microsemi GE VSC8514 SyncE] (irq=POLL)
[ 7.437516] mscc_felix 0000:00:00.5: nonfatal error -34 setting MTU to 1500 on port 0
[ 7.588585] mscc_felix 0000:00:00.5 swp1 (uninitialized): PHY [0000:00:00.3:11] driver [Microsemi GE VSC8514 SyncE] (irq=POLL)
[ 7.600433] mscc_felix 0000:00:00.5: nonfatal error -34 setting MTU to 1500 on port 1
[ 7.752613] mscc_felix 0000:00:00.5 swp2 (uninitialized): PHY [0000:00:00.3:12] driver [Microsemi GE VSC8514 SyncE] (irq=POLL)
[ 7.764457] mscc_felix 0000:00:00.5: nonfatal error -34 setting MTU to 1500 on port 2
[ 7.900771] mscc_felix 0000:00:00.5 swp3 (uninitialized): PHY [0000:00:00.3:13] driver [Microsemi GE VSC8514 SyncE] (irq=POLL)
[ 7.912501] mscc_felix 0000:00:00.5: nonfatal error -34 setting MTU to 1500 on port 3

I wonder, shouldn't we first fix that, and apply this patch set afterwards?

\
 
 \ /
  Last update: 2023-03-26 23:31    [W:0.387 / U:1.268 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site