On 18/10/2022 23:45, Mah, Yock Gen wrote:
-----Original Message-----
From: Kevin Traynor <ktray...@redhat.com>
Sent: Tuesday, 18 October, 2022 8:54 PM
To: Mah, Yock Gen <yock.gen....@intel.com>; IOTG DPDK Ref App
<iotg.dpdk.ref....@intel.com>; Zhang, Qi Z <qi.z.zh...@intel.com>
Cc: dev@dpdk.org
Subject: Re: [PATCH v2] IGC: Remove I225_I_PHY_ID checking
On 12/10/2022 09:39, Kevin Traynor wrote:
On 12/10/2022 08:45, Mah, Yock Gen wrote:
-----Original Message-----
From: Kevin Traynor <ktray...@redhat.com>
Sent: Tuesday, 11 October, 2022 7:05 PM
To: IOTG DPDK Ref App <iotg.dpdk.ref....@intel.com>; Zhang, Qi Z
<qi.z.zh...@intel.com>
Cc: dev@dpdk.org
Subject: Re: [PATCH v2] IGC: Remove I225_I_PHY_ID checking
On 31/08/2022 23:51, iotg.dpdk.ref....@intel.com wrote:
From: NSWE SWS DPDK Dev <iotg.dpdk.ref....@intel.com>
i225 devices have only one PHY vendor. There is unnecessary to check
_I_PHY_ID during the link establishment and auto-negotiation
process, the checking also caused devices like i225-IT failed. This
patch is to remove the mentioned unnecessary checking.
Cc: sta...@dpdk.org
Signed-off-by: NSWE SWS DPDK Dev <iotg.dpdk.ref....@intel.com>
---
drivers/net/igc/base/igc_i225.c | 15 ++-------------
drivers/net/igc/base/igc_phy.c | 6 ++----
2 files changed, 4 insertions(+), 17 deletions(-)
diff --git a/drivers/net/igc/base/igc_i225.c
b/drivers/net/igc/base/igc_i225.c index 5f3d535490..af26602afb
100644
--- a/drivers/net/igc/base/igc_i225.c
+++ b/drivers/net/igc/base/igc_i225.c
@@ -173,19 +173,8 @@ static s32 igc_init_phy_params_i225(struct igc_hw *hw)
phy->ops.write_reg = igc_write_phy_reg_gpy;
ret_val = igc_get_phy_id(hw);
- /* Verify phy id and set remaining function pointers */
- switch (phy->id) {
- case I225_I_PHY_ID:
- case I226_LM_PHY_ID:
- phy->type = igc_phy_i225;
- phy->ops.set_d0_lplu_state = igc_set_d0_lplu_state_i225;
- phy->ops.set_d3_lplu_state = igc_set_d3_lplu_state_i225;
- The commit log says it is removing a check on the ID, but it does not say why
these function pointers are being removed.
- Why are they removed, were they not needed?
i225 devices have only one PHY vendor. There is no point checking _I_PHY_ID
during the link establishment and auto-negotiation process.
Right, that's clear about the vendor ID check. But it's not clear to
me why the the resulting code like this:
phy->type = igc_phy_i225;
and not like this:
phy->type = igc_phy_i225;
phy->ops.set_d0_lplu_state = igc_set_d0_lplu_state_i225;
phy->ops.set_d3_lplu_state = igc_set_d3_lplu_state_i225;
So it is using dummy null functions instead:
https://git.dpdk.org/dpdk/tree/drivers/net/igc/base/igc_phy.c#n61
Do the device registers not need to be set anymore?
For main branch, it would be nice to have an answer to above.
It only adds a small readability benefit by removing some code branches, but
does change functionality which adds risk, so I don't think it's a good
candidate for stable branches.
This is not only added readability, but to fix real world issue, we were
experiencing i225-IT not runnable issue without patching another case checking
as below:
+++ b/drivers/net/igc/base/igc_phy.c
@@ -1881,6 +1881,7 @@ s32 igc_phy_force_speed_duplex_m88(struct igc_hw *hw)
case I210_I_PHY_ID:
/* fall-through */
case I225_I_PHY_ID:
+ case I225_IT_PHY_ID:
However, cleaner solution is to remove those unnecessary checking completely as
it does in kernel also
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c496de538eebd8212dc2a3c9a468386b264d0d4
ok, you are correct that it is more than readability. I can apply but
first it would be good if you can answer the original question and
explain why the functionality is changed for I225_I_PHY_ID by removing
the function pointers that set the registers.
- /* TODO - complete with GPY PHY information */
- break;
- default:
- ret_val = -IGC_ERR_PHY;
- goto out;
- }
+ phy->type = igc_phy_i225;
+
out:
return ret_val;
diff --git a/drivers/net/igc/base/igc_phy.c
b/drivers/net/igc/base/igc_phy.c index 43bbe69bca..2906bae21a 100644
--- a/drivers/net/igc/base/igc_phy.c
+++ b/drivers/net/igc/base/igc_phy.c
@@ -1474,8 +1474,7 @@ s32 igc_phy_setup_autoneg(struct igc_hw *hw)
return ret_val;
}
- if ((phy->autoneg_mask & ADVERTISE_2500_FULL) &&
- hw->phy.id == I225_I_PHY_ID) {
+ if (phy->autoneg_mask & ADVERTISE_2500_FULL) {
/* Read the MULTI GBT AN Control Register - reg 7.32 */
ret_val = phy->ops.read_reg(hw, (STANDARD_AN_REG_MASK <<
MMD_DEVADDR_SHIFT) |
@@ -1615,8 +1614,7 @@ s32 igc_phy_setup_autoneg(struct igc_hw *hw)
ret_val = phy->ops.write_reg(hw, PHY_1000T_CTRL,
mii_1000t_ctrl_reg);
- if ((phy->autoneg_mask & ADVERTISE_2500_FULL) &&
- hw->phy.id == I225_I_PHY_ID)
+ if (phy->autoneg_mask & ADVERTISE_2500_FULL)
ret_val = phy->ops.write_reg(hw,
(STANDARD_AN_REG_MASK <<
MMD_DEVADDR_SHIFT) |
