| Message ID | 20201119064020.19522-1-dqfext@gmail.com (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [RFC,net-next] net: dsa: mt7530: support setting ageing time | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for net-next |
| netdev/subject_prefix | success | Link |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 72 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/header_inline | success | Link |
| netdev/stable | success | Stable not CCed |
On Thu, Nov 19, 2020 at 02:40:20PM +0800, DENG Qingfang wrote: > MT7530 has a global address age control register, so use it to set > ageing time. > > The applied timer is (AGE_CNT + 1) * (AGE_UNIT + 1) seconds > > Signed-off-by: DENG Qingfang <dqfext@gmail.com> > --- > drivers/net/dsa/mt7530.c | 41 ++++++++++++++++++++++++++++++++++++++++ > drivers/net/dsa/mt7530.h | 13 +++++++++++++ > 2 files changed, 54 insertions(+) > > RFC: > 1. What is the expected behaviour if the timer is too big or too small? > - return -ERANGE or -EINVAL; ERANGE is good. > or > - if it is too big, apply the maximum value; if it is too small, > disable learning; > > 2. Is there a better algorithm to find the closest pair? The bridge code will default to 300 seconds. And after a topology change, it sets it to 2 * the forwarding delay, which defaults to 15 seconds. So maybe you can look for these two values, and use pre-computed values? You still need to handle other values, the user can configure these. Andrew
On Fri, Nov 20, 2020 at 10:26 AM Andrew Lunn <andrew@lunn.ch> wrote: > The bridge code will default to 300 seconds. And after a topology > change, it sets it to 2 * the forwarding delay, which defaults to 15 > seconds. So maybe you can look for these two values, and use > pre-computed values? 15 and 300 are not larger than 4096 (AGE_UNIT_MAX + 1) so the exact match can always be found in the first iteration: age_count = 0, age_unit = 14, secs = (0 + 1) * (14 + 1) = 15 age_count = 0, age_unit = 299, secs = (0 + 1) * (299 + 1) = 300 > > You still need to handle other values, the user can configure these. > > Andrew
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c index 6408402a44f5..99bf8fed6536 100644 --- a/drivers/net/dsa/mt7530.c +++ b/drivers/net/dsa/mt7530.c @@ -870,6 +870,46 @@ mt7530_get_sset_count(struct dsa_switch *ds, int port, int sset) return ARRAY_SIZE(mt7530_mib); } +static int +mt7530_set_ageing_time(struct dsa_switch *ds, unsigned int msecs) +{ + struct mt7530_priv *priv = ds->priv; + unsigned int secs = msecs / 1000; + unsigned int tmp_age_count; + unsigned int error = -1; + unsigned int age_count; + unsigned int age_unit; + + /* Applied timer is (AGE_CNT + 1) * (AGE_UNIT + 1) seconds */ + if (secs < 1 || secs > (AGE_CNT_MAX + 1) * (AGE_UNIT_MAX + 1)) + return -ERANGE; + + /* iterate through all possible age_count to find the closest pair */ + for (tmp_age_count = 0; tmp_age_count <= AGE_CNT_MAX; ++tmp_age_count) { + unsigned int tmp_age_unit = secs / (tmp_age_count + 1) - 1; + + if (tmp_age_unit <= AGE_UNIT_MAX) { + unsigned int tmp_error = secs - + (tmp_age_count + 1) * (tmp_age_unit + 1); + + /* found a closer pair */ + if (error > tmp_error) { + error = tmp_error; + age_count = tmp_age_count; + age_unit = tmp_age_unit; + } + + /* found the exact match, so break the loop */ + if (!error) + break; + } + } + + mt7530_write(priv, MT7530_AAC, AGE_CNT(age_count) | AGE_UNIT(age_unit)); + + return 0; +} + static void mt7530_setup_port5(struct dsa_switch *ds, phy_interface_t interface) { struct mt7530_priv *priv = ds->priv; @@ -2564,6 +2604,7 @@ static const struct dsa_switch_ops mt7530_switch_ops = { .phy_write = mt753x_phy_write, .get_ethtool_stats = mt7530_get_ethtool_stats, .get_sset_count = mt7530_get_sset_count, + .set_ageing_time = mt7530_set_ageing_time, .port_enable = mt7530_port_enable, .port_disable = mt7530_port_disable, .port_change_mtu = mt7530_port_change_mtu, diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h index ee3523a7537e..32d8969b3ace 100644 --- a/drivers/net/dsa/mt7530.h +++ b/drivers/net/dsa/mt7530.h @@ -161,6 +161,19 @@ enum mt7530_vlan_egress_attr { MT7530_VLAN_EGRESS_STACK = 3, }; +/* Register for address age control */ +#define MT7530_AAC 0xa0 +/* Disable ageing */ +#define AGE_DIS BIT(20) +/* Age count */ +#define AGE_CNT_MASK GENMASK(19, 12) +#define AGE_CNT_MAX 0xff +#define AGE_CNT(x) (AGE_CNT_MASK & ((x) << 12)) +/* Age unit */ +#define AGE_UNIT_MASK GENMASK(11, 0) +#define AGE_UNIT_MAX 0xfff +#define AGE_UNIT(x) (AGE_UNIT_MASK & (x)) + /* Register for port STP state control */ #define MT7530_SSP_P(x) (0x2000 + ((x) * 0x100)) #define FID_PST(x) ((x) & 0x3)
MT7530 has a global address age control register, so use it to set ageing time. The applied timer is (AGE_CNT + 1) * (AGE_UNIT + 1) seconds Signed-off-by: DENG Qingfang <dqfext@gmail.com> --- drivers/net/dsa/mt7530.c | 41 ++++++++++++++++++++++++++++++++++++++++ drivers/net/dsa/mt7530.h | 13 +++++++++++++ 2 files changed, 54 insertions(+) RFC: 1. What is the expected behaviour if the timer is too big or too small? - return -ERANGE or -EINVAL; or - if it is too big, apply the maximum value; if it is too small, disable learning; 2. Is there a better algorithm to find the closest pair?