Commit f20a0a05 authored by Vincent Mailhol's avatar Vincent Mailhol Committed by Jakub Kicinski

ethtool: doc: clarify what drivers can implement in their get_drvinfo()

Many of the drivers which implement ethtool_ops::get_drvinfo() will
prints the .driver, .version or .bus_info of struct ethtool_drvinfo.
To have a glance of current state, do:

  $ git grep -W "get_drvinfo(struct"

Printing in those three fields is useless because:

  - since [1], the driver version should be the kernel version (at
    least for upstream drivers). Arguably, out of tree drivers might
    still want to set a custom version, but out of tree is not our
    focus.

  - since [2], the core is able to provide default values for .driver
    and .bus_info.

In summary, drivers may provide .fw_version and .erom_version, the
rest is expected to be done by the core.

In struct ethtool_ops doc from linux/ethtool: rephrase field
get_drvinfo() doc to discourage developers from implementing this
callback.

In struct ethtool_drvinfo doc from uapi/linux/ethtool.h: remove the
paragraph mentioning what drivers should do. Rationale: no need to
repeat what is already written in struct ethtool_ops doc. But add a
note that .fw_version and .erom_version are driver defined.

Also update the dummy driver and simply remove the callback in order
not to confuse the newcomers: most of the drivers will not need this
callback function any more.

[1] commit 6a7e25c7 ("net/core: Replace driver version to be
    kernel version")
Link: https://git.kernel.org/torvalds/linux/c/6a7e25c7fb48

[2] commit edaf5df2 ("ethtool: ethtool_get_drvinfo: populate
    drvinfo fields even if callback exits")
Link: https://git.kernel.org/netdev/net-next/c/edaf5df22cb8Reviewed-by: default avatarLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: default avatarVincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20221116171828.4093-1-mailhol.vincent@wanadoo.frSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 224b744a
......@@ -99,14 +99,7 @@ static const struct net_device_ops dummy_netdev_ops = {
.ndo_change_carrier = dummy_change_carrier,
};
static void dummy_get_drvinfo(struct net_device *dev,
struct ethtool_drvinfo *info)
{
strscpy(info->driver, DRV_NAME, sizeof(info->driver));
}
static const struct ethtool_ops dummy_ethtool_ops = {
.get_drvinfo = dummy_get_drvinfo,
.get_ts_info = ethtool_op_get_ts_info,
};
......
......@@ -473,10 +473,10 @@ struct ethtool_module_power_mode_params {
* parameter.
* @supported_coalesce_params: supported types of interrupt coalescing.
* @supported_ring_params: supported ring params.
* @get_drvinfo: Report driver/device information. Should only set the
* @driver, @version, @fw_version and @bus_info fields. If not
* implemented, the @driver and @bus_info fields will be filled in
* according to the netdev's parent device.
* @get_drvinfo: Report driver/device information. Modern drivers no
* longer have to implement this callback. Most fields are
* correctly filled in by the core using system information, or
* populated using other driver operations.
* @get_regs_len: Get buffer length required for @get_regs
* @get_regs: Get device registers
* @get_wol: Report whether Wake-on-Lan is enabled
......
......@@ -159,8 +159,10 @@ static inline __u32 ethtool_cmd_speed(const struct ethtool_cmd *ep)
* in its bus driver structure (e.g. pci_driver::name). Must
* not be an empty string.
* @version: Driver version string; may be an empty string
* @fw_version: Firmware version string; may be an empty string
* @erom_version: Expansion ROM version string; may be an empty string
* @fw_version: Firmware version string; driver defined; may be an
* empty string
* @erom_version: Expansion ROM version string; driver defined; may be
* an empty string
* @bus_info: Device bus address. This should match the dev_name()
* string for the underlying bus device, if there is one. May be
* an empty string.
......@@ -179,10 +181,6 @@ static inline __u32 ethtool_cmd_speed(const struct ethtool_cmd *ep)
*
* Users can use the %ETHTOOL_GSSET_INFO command to get the number of
* strings in any string set (from Linux 2.6.34).
*
* Drivers should set at most @driver, @version, @fw_version and
* @bus_info in their get_drvinfo() implementation. The ethtool
* core fills in the other fields using other driver operations.
*/
struct ethtool_drvinfo {
__u32 cmd;
......
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