[PATCHv2 0/4] ethtool: generalize use of ethtool_cmd_speed API

David Decotigny
2011-04-27T18:35:23Z

Hi all,

This is the second version of a patch series aimed at making sure the
speed field of struct ethtool_cmd is accessed as a 32b integer
throughout the kernel.

Thanks to Ben for his careful review!
Below are a few comments before sending the series.

On 04/16/11 19:06, Ben Hutchings wrote:
> Don't encourage use of the SPEED_* macros. The speed is just a value in
> units of Mbit/s.

Updated. Thanks!

>> This makes sure that when a driver calls the ethtool's
>> get/set_settings() callback of another driver,
>
> Many of them are calling themselves, and they can ignore speed_hi
> because they will never set it.

Right. Here is what I replied to Ben in private: I think it makes
sense to have a uniform & consistent use of the API without exception
nor assumption, even though it borrows additional useless CPU cycles
(+ cache lines probably). This comes down to trade-off between code
management and performance, for which I privileged the former because
I don't think the ethtool api is supposed to be heavily used
throughout normal kernel operation.

I left the initial changes in place.

>> the data passed to it
>> is clean. This guarantees that speed_hi will be zeroed correctly if
>> the called callback doesn't explicitely set it: we are sure we don't
>> get a corrupted speed from the underlying driver. We also take care of
>> setting the cmd field appropriately (ETHTOOL_GSET/SSET).
>
> I think this initialisation ought to be done in
> dev_ethtool_get_settings(), and that function moved into net/core/dev.c,
> to avoid code bloat. (Yes it's minimal in this case, but these things
> add up.)

Done. This is in the 2nd patch of the series. Any feedback welcome, I
am not entirely convinced that my additions are pertinent.

> Maybe also in mii_ethtool_gset().

I don't think this is equivalent to dev_ethtool_get_settings(). My
understanding is that mii_ethtool_gset() (and likewise for mdio45_) is
meant to be wrapped almost transparently inside a driver's
get_settings(), so it should make the same assumptions as a normal
get_settings(). However, dev_ethtool_get_settings() is meant to be
used to _call_ some driver's get_settings(), so it should make sure
that it enforces the assumptions this driver is making.

In the end, I didn't change mii_ethtool_gset() the same way I did for
dev_ethtool_get_settings (no memset).

>> --- a/arch/mips/txx9/generic/setup_tx4939.c
>> +++ b/arch/mips/txx9/generic/setup_tx4939.c
[...]
> If you're going to rewrite the whole function then at least get rid of
> this stupid conditional and return ethtool_cmd_speed(&cmd).

Updated. Thanks!

[...]
> e100 is just getting its own settings and doesn't need to be changed.

Right. I still did change it for the sake of consistency (see remark
above).

[...]
>> diff --git a/drivers/net/pcnet32.c b/drivers/net/pcnet32.c
>> @@ -2763,11 +2763,12 @@ static void pcnet32_check_media(struct net_device *dev, int verbose)
>> netif_carrier_on(dev);
>> if (lp->mii) {
>> if (netif_msg_link(lp)) {
>> - struct ethtool_cmd ecmd;
>> + struct ethtool_cmd ecmd = {
>> + .cmd = ETHTOOL_GSET };
>> mii_ethtool_gset(&lp->mii_if, &ecmd);
>> netdev_info(dev, "link up, %sMbps, %s-duplex\n",
>> - (ecmd.speed == SPEED_100)
>> - ? "100" : "10",
>> + (ethtool_cmd_speed(&ecmd)
>> + == SPEED_100) ? "100" : "10",
>
> Just use ethtool_cmd_speed() and %u rather than this conditional.

Updated. Thanks!

[...]
>> diff --git a/drivers/net/stmmac/stmmac_ethtool.c b/drivers/net/stmmac/stmmac_ethtool.c
>> index 0e61ac8..33cf0b1 100644
>> --- a/drivers/net/stmmac/stmmac_ethtool.c
>> +++ b/drivers/net/stmmac/stmmac_ethtool.c
>> @@ -237,13 +237,13 @@ stmmac_set_pauseparam(struct net_device *netdev,
>>
>> if (phy->autoneg) {
>> if (netif_running(netdev)) {
>> - struct ethtool_cmd cmd;
>> + struct ethtool_cmd cmd = { .cmd = ETHTOOL_SSET };
>> /* auto-negotiation automatically restarted */
>> cmd.cmd = ETHTOOL_NWAY_RST;
>
> This line immediately changes cmd.cmd. The original author is clearly
> confused, as the phy_ethtool_sset() ignores cmd.cmd and ETHTOOL_NWAY_RST
> does not take any parameters.

True. I made this a bit more elegant.

> I think this whole block should really just be:
>
> ret = phy_start_aneg(phy);

Right, but I prefer not to do this in this series.

> [...]
>> diff --git a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
>> index e2e6475..6df9540 100644
>> --- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
>> +++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
>> @@ -664,22 +664,28 @@ static void bnx2fc_link_speed_update(struct fc_lport *lport)
[...]
> This restructuring looks entirely unnecessary, and obscures the real
> change being made.

That's definitely true. Made my changes more transparent. Thanks!

>> diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
>> index bde6ee5..ba9e84a 100644
>> --- a/drivers/scsi/fcoe/fcoe.c
>> +++ b/drivers/scsi/fcoe/fcoe.c
>> @@ -2026,25 +2026,30 @@ out_nodev:
>> int fcoe_link_speed_update(struct fc_lport *lport)
>> {
> [...]
>
> Ditto here.

Same here.

On 04/16/11 19:02, Ben Hutchings wrote:
> On Sat, 2011-04-16 at 17:54 -0700, David Decotigny wrote:
>> This makes sure the ethtool's set_settings() callback of network
>> drivers don't ignore the 16 most significant bits when ethtool calls
>> their set_settings().
>>
>> All the driver compiled with make allyesconfig on x86_64 have been
>> updated.
>
> You missed one generic function, mdio45_ethtool_gset_npage() in
> drivers/net/mdio.c.

I am not sure about this one. But I think it falls in the same
category as mii_ethtool_gset() above.

>
> [...]
>> diff --git a/drivers/net/dl2k.c b/drivers/net/dl2k.c
>> index c05db60..ba6c151 100644
>> --- a/drivers/net/dl2k.c
>> +++ b/drivers/net/dl2k.c
>> @@ -1219,11 +1219,11 @@ static int rio_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
>> } else {
>> np->an_enable = 0;
>> if (np->speed == 1000) {
>> - cmd->speed = SPEED_100;
>> + ethtool_cmd_speed_set(cmd, SPEED_100);
>> cmd->duplex = DUPLEX_FULL;
>> printk("Warning!! Can't disable Auto negotiation in 1000Mbps, change to Manual 100Mbps, Full duplex.\n");
>> }
>> - switch(cmd->speed + cmd->duplex) {
>> + switch (ethtool_cmd_speed(cmd) + cmd->duplex) {
> [...]
>
> If you're going to stop these drivers ignoring speed_hi, maybe you
> should also stop them ignoring the difference between speed and duplex!
> Currently the user can ask for 99 Mbit/s full-duplex and get 100 Mbit/s
> half-duplex.

Yes, that is completely right. Updated. Thanks!

>
> There are several others that use this trick.

Yes, I noticed too (e1000(e)) but I think it would deserve another
set of patches.

David Decotigny (4):
ethtool: cosmetics: enforce const-ness in ethtool_cmd_speed
ethtool: Call ethtool's get/set_settings callbacks with cleaned data
ethtool: Use the full 32 bit speed range in ethtool's set_settings
ethtool: cosmetic: Use ethtool ethtool_cmd_speed API

arch/mips/txx9/generic/setup_tx4939.c | 21 ++++++-----------
drivers/infiniband/hw/nes/nes_nic.c | 4 +-
drivers/net/3c509.c | 2 +-
drivers/net/acenic.c | 10 ++++----
drivers/net/arm/etherh.c | 5 ++-
drivers/net/arm/ks8695net.c | 7 +++--
drivers/net/atl1c/atl1c_ethtool.c | 9 ++++---
drivers/net/atl1e/atl1e_ethtool.c | 4 +-
drivers/net/atlx/atl1.c | 9 ++++---
drivers/net/atlx/atl2.c | 4 +-
drivers/net/b44.c | 13 ++++++-----
drivers/net/bcm63xx_enet.c | 3 +-
drivers/net/benet/be_ethtool.c | 16 ++++++------
drivers/net/bna/bnad_ethtool.c | 7 +++--
drivers/net/bnx2.c | 19 +++++++--------
drivers/net/cassini.c | 37 ++++++++++++++++---------------
drivers/net/chelsio/cxgb2.c | 11 +++++----
drivers/net/cxgb3/cxgb3_main.c | 14 ++++++-----
drivers/net/cxgb4/cxgb4_main.c | 14 ++++++-----
drivers/net/cxgb4vf/cxgb4vf_main.c | 3 +-
drivers/net/dl2k.c | 29 ++++++++++--------------
drivers/net/e100.c | 10 +++++---
drivers/net/e1000/e1000_ethtool.c | 10 +++++---
drivers/net/e1000e/ethtool.c | 15 +++++++-----
drivers/net/eepro.c | 2 +-
drivers/net/ehea/ehea_ethtool.c | 23 +++++++++++++++----
drivers/net/enc28j60.c | 5 ++-
drivers/net/enic/enic_main.c | 4 +-
drivers/net/ewrk3.c | 2 +-
drivers/net/forcedeth.c | 25 ++++++++++++--------
drivers/net/ibmveth.c | 2 +-
drivers/net/igb/igb_ethtool.c | 11 +++++----
drivers/net/igbvf/ethtool.c | 8 +++---
drivers/net/ixgb/ixgb_ethtool.c | 7 +++--
drivers/net/ixgbe/ixgbe_ethtool.c | 11 +++++----
drivers/net/ixgbevf/ethtool.c | 8 ++++--
drivers/net/jme.c | 3 +-
drivers/net/ksz884x.c | 9 ++++---
drivers/net/mdio.c | 22 +++++++++++------
drivers/net/mii.c | 31 ++++++++++++++++----------
drivers/net/mlx4/en_ethtool.c | 7 +++--
drivers/net/mv643xx_eth.c | 6 ++--
drivers/net/myri10ge/myri10ge.c | 2 +-
drivers/net/natsemi.c | 11 +++++----
drivers/net/netxen/netxen_nic_ethtool.c | 15 ++++++------
drivers/net/niu.c | 4 +-
drivers/net/ns83820.c | 8 +++---
drivers/net/pch_gbe/pch_gbe_ethtool.c | 9 ++++---
drivers/net/pch_gbe/pch_gbe_main.c | 6 ++--
drivers/net/pch_gbe/pch_gbe_phy.c | 4 +-
drivers/net/pcmcia/smc91c92_cs.c | 6 ++--
drivers/net/pcnet32.c | 16 ++++++------
drivers/net/phy/phy.c | 12 ++++++----
drivers/net/ps3_gelic_net.c | 8 +++---
drivers/net/qla3xxx.c | 2 +-
drivers/net/qlcnic/qlcnic_ethtool.c | 12 +++++-----
drivers/net/qlge/qlge_ethtool.c | 2 +-
drivers/net/r8169.c | 5 ++-
drivers/net/s2io.c | 6 ++--
drivers/net/sc92031.c | 8 ++++--
drivers/net/sfc/ethtool.c | 5 ++-
drivers/net/sfc/mcdi_phy.c | 6 ++--
drivers/net/sfc/mdio_10g.c | 4 +-
drivers/net/sfc/tenxpress.c | 2 +-
drivers/net/skge.c | 6 ++--
drivers/net/sky2.c | 8 +++---
drivers/net/smc911x.c | 4 +-
drivers/net/smc91x.c | 4 +-
drivers/net/spider_net_ethtool.c | 2 +-
drivers/net/stmmac/stmmac_ethtool.c | 5 +--
drivers/net/sungem.c | 15 ++++++------
drivers/net/sunhme.c | 19 +++++++--------
drivers/net/tehuti.c | 2 +-
drivers/net/tg3.c | 13 ++++++-----
drivers/net/tulip/de2104x.c | 11 +++++----
drivers/net/tulip/uli526x.c | 6 ++--
drivers/net/tun.c | 2 +-
drivers/net/typhoon.c | 19 ++++++++-------
drivers/net/usb/asix.c | 28 ++++++++++++-----------
drivers/net/usb/catc.c | 2 +-
drivers/net/usb/dm9601.c | 6 ++--
drivers/net/usb/rtl8150.c | 11 +++++----
drivers/net/usb/smsc75xx.c | 7 +++--
drivers/net/usb/smsc95xx.c | 7 +++--
drivers/net/veth.c | 2 +-
drivers/net/via-velocity.c | 21 +++++++++++------
drivers/net/vmxnet3/vmxnet3_ethtool.c | 4 +-
drivers/net/vxge/vxge-ethtool.c | 7 +++--
drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 11 ++++++---
drivers/scsi/fcoe/fcoe.c | 11 ++++++---
include/linux/ethtool.h | 18 +++++++++++----
include/linux/netdevice.h | 9 +------
include/rdma/ib_addr.h | 13 ++++++-----
net/batman-adv/soft-interface.c | 2 +-
net/bridge/br_if.c | 4 +-
net/core/dev.c | 24 ++++++++++++++++++++
net/core/net-sysfs.c | 24 ++++++++-----------
97 files changed, 522 insertions(+), 420 deletions(-)

--
1.7.3.1