Message ID | 20231227044347.107291-7-arinc.unal@arinc9.com (mailing list archive) |
---|---|
State | Deferred |
Delegated to: | Netdev Maintainers |
Headers | show |
Series | MT7530 DSA Subdriver Improvements Act I | expand |
On Wed, Dec 27, 2023 at 07:43:46AM +0300, Arınç ÜNAL wrote: > priv->p5_interface and priv->p6_interface are for use on the MT7531 switch. > They prevent the CPU ports of MT7531 to be configured again. They are > useless for MT7530. Therefore, remove setting priv->p5_interface for > MT7530. > > Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com> > --- What makes priv->p5_interface and priv->p6_interface useless for MT7530 as you say? This code in mt753x_phylink_mac_config() seems executed regardless of switch family: case 5: if (priv->p5_interface == state->interface) break; if (mt753x_mac_config(ds, port, mode, state) < 0) goto unsupported; if (priv->p5_intf_sel != P5_DISABLED) priv->p5_interface = state->interface; break; case 6: if (priv->p6_interface == state->interface) break; mt753x_pad_setup(ds, state); if (mt753x_mac_config(ds, port, mode, state) < 0) goto unsupported; priv->p6_interface = state->interface; break;
On 4.01.2024 18:42, Vladimir Oltean wrote: > On Wed, Dec 27, 2023 at 07:43:46AM +0300, Arınç ÜNAL wrote: >> priv->p5_interface and priv->p6_interface are for use on the MT7531 switch. >> They prevent the CPU ports of MT7531 to be configured again. They are >> useless for MT7530. Therefore, remove setting priv->p5_interface for >> MT7530. >> >> Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com> >> --- > > What makes priv->p5_interface and priv->p6_interface useless for MT7530 > as you say? This code in mt753x_phylink_mac_config() seems executed > regardless of switch family: > > case 5: > if (priv->p5_interface == state->interface) > break; > > if (mt753x_mac_config(ds, port, mode, state) < 0) > goto unsupported; > > if (priv->p5_intf_sel != P5_DISABLED) > priv->p5_interface = state->interface; > break; > case 6: > if (priv->p6_interface == state->interface) > break; > > mt753x_pad_setup(ds, state); > > if (mt753x_mac_config(ds, port, mode, state) < 0) > goto unsupported; > > priv->p6_interface = state->interface; > break; This is also useless for non-MT7531 switches in the sense that it unnecessarily prevents port 5 and 6 from being reconfigured. There's nothing wrong with configuring them multiple times. These are the remains of before phylink was implemented on this driver so the thought of changing phy_interface_t on the fly was non existent. At that time, it was probably made to apply to all switch models for convenience, as port 5 and 6 are CPU ports so they're highly likely to be fixed links. The reason I don't deal with this code block now is because I will get rid of priv->p5_interface and priv->p6_interface when I also get rid of priv->info->cpu_port_config() with a later patch. Arınç
On 6.01.2024 18:00, Arınç ÜNAL wrote: > On 4.01.2024 18:42, Vladimir Oltean wrote: >> On Wed, Dec 27, 2023 at 07:43:46AM +0300, Arınç ÜNAL wrote: >>> priv->p5_interface and priv->p6_interface are for use on the MT7531 switch. >>> They prevent the CPU ports of MT7531 to be configured again. They are >>> useless for MT7530. Therefore, remove setting priv->p5_interface for >>> MT7530. >>> >>> Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com> >>> --- >> >> What makes priv->p5_interface and priv->p6_interface useless for MT7530 >> as you say? This code in mt753x_phylink_mac_config() seems executed >> regardless of switch family: >> >> case 5: >> if (priv->p5_interface == state->interface) >> break; >> >> if (mt753x_mac_config(ds, port, mode, state) < 0) >> goto unsupported; >> >> if (priv->p5_intf_sel != P5_DISABLED) >> priv->p5_interface = state->interface; >> break; >> case 6: >> if (priv->p6_interface == state->interface) >> break; >> >> mt753x_pad_setup(ds, state); >> >> if (mt753x_mac_config(ds, port, mode, state) < 0) >> goto unsupported; >> >> priv->p6_interface = state->interface; >> break; > > This is also useless for non-MT7531 switches in the sense that it > unnecessarily prevents port 5 and 6 from being reconfigured. There's > nothing wrong with configuring them multiple times. These are the remains > of before phylink was implemented on this driver so the thought of changing > phy_interface_t on the fly was non existent. At that time, it was probably > made to apply to all switch models for convenience, as port 5 and 6 are CPU > ports so they're highly likely to be fixed links. > > The reason I don't deal with this code block now is because I will get rid > of priv->p5_interface and priv->p6_interface when I also get rid of > priv->info->cpu_port_config() with a later patch. Sorry, I couldn't give a straight answer. Here's the exact answer to this patch. Running mt7530_setup_port5() from mt7530_setup() handles all cases of configuring port 5, including phylink. Setting priv->p5_interface under mt7530_setup_port5() makes sure that mt7530_setup_port5() from mt753x_phylink_mac_config() won't run. The ("net: dsa: mt7530: improve code path for setting up port 5") patch makes so that mt7530_setup_port5() from mt7530_setup() runs only on non-phylink cases. So we get rid of setting priv->p5_interface under mt7530_setup_port5() as port 5 phylink configuration will be done by running mt7530_setup_port5() from mt753x_phylink_mac_config() now. Running mt7530_setup_port5() from mt753x_phylink_mac_config() multiple times is being prevented which shouldn't be done. That's because of a different reason involving MT7531. I will deal with this with a later patch. I intend to put this on the patch log. Arınç
On Tue, Jan 09, 2024 at 02:42:45PM +0300, Arınç ÜNAL wrote: > Running mt7530_setup_port5() from mt753x_phylink_mac_config() multiple > times is being prevented which shouldn't be done. That's because of a > different reason involving MT7531. I will deal with this with a later > patch. > > I intend to put this on the patch log. Still not clear why it shouldn't be done. Ideally you could come up with a plausible hypothesis as to why it's there in the first place, and why it's not needed.
On 9.01.2024 14:51, Vladimir Oltean wrote: > On Tue, Jan 09, 2024 at 02:42:45PM +0300, Arınç ÜNAL wrote: >> Running mt7530_setup_port5() from mt753x_phylink_mac_config() multiple >> times is being prevented which shouldn't be done. That's because of a >> different reason involving MT7531. I will deal with this with a later >> patch. >> >> I intend to put this on the patch log. > > Still not clear why it shouldn't be done. Ideally you could come up with > a plausible hypothesis as to why it's there in the first place, and why > it's not needed. I can't tell why it's there. Russell did analyse why it's not needed [1] and my test [2] confirms it. This patch is about removing the unnecessary setting of priv->p5_interface on mt7530_setup_port5() which I believe I have already explained. I would like to get into the details of priv->p5_interface and priv->p6_interface when I remove them along with cpu_port_config(). That said, I will refrain from including the last paragraph on the patch log. [1] https://lore.kernel.org/netdev/ZHy2jQLesdYFMQtO@shell.armlinux.org.uk/ [2] https://lore.kernel.org/netdev/9308fa1a-6de3-490b-9aeb-eb207b0432df@arinc9.com/ Arınç
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c index bf6c59ecc489..07c5f1c6d036 100644 --- a/drivers/net/dsa/mt7530.c +++ b/drivers/net/dsa/mt7530.c @@ -978,8 +978,6 @@ static void mt7530_setup_port5(struct dsa_switch *ds, phy_interface_t interface) dev_dbg(ds->dev, "Setup P5, HWTRAP=0x%x, intf_sel=%s, phy-mode=%s\n", val, p5_intf_modes(priv->p5_intf_sel), phy_modes(interface)); - priv->p5_interface = interface; - unlock_exit: mutex_unlock(&priv->reg_mutex); }
priv->p5_interface and priv->p6_interface are for use on the MT7531 switch. They prevent the CPU ports of MT7531 to be configured again. They are useless for MT7530. Therefore, remove setting priv->p5_interface for MT7530. Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com> --- drivers/net/dsa/mt7530.c | 2 -- 1 file changed, 2 deletions(-)