Re: [Intel-wired-lan] [PATCH 1/3] e1000e: Remove redundant runtime resume for ethtool_ops

naamax.meir
2024-04-02T18:32:37Z

On 3/26/2024 00:29, Bjorn Helgaas wrote:
> From: Bjorn Helgaas <bhelgaas@google.com>
>
> e60b22c5b7e5 ("e1000e: fix accessing to suspended device") added
> ethtool_ops.begin() and .complete(), which used pm_runtime_get_sync() to
> resume suspended devices before any ethtool_ops callback and allow suspend
> after it completed.
>
> 3ef672ab1862 ("e1000e: ethtool unnecessarily takes device out of RPM
> suspend") removed ethtool_ops.begin() and .complete() and instead did
> pm_runtime_get_sync() only in the individual ethtool_ops callbacks that
> access device registers.
>
> Subsequently, f32a21376573 ("ethtool: runtime-resume netdev parent before
> ethtool ioctl ops") added pm_runtime_get_sync() in the dev_ethtool() path,
> so the device is resumed before *any* ethtool_ops callback, as it was
> before 3ef672ab1862.
>
> Remove most runtime resumes from ethtool_ops, which are now redundant
> because the resume has already been done by dev_ethtool(). This is
> essentially a revert of 3ef672ab1862 ("e1000e: ethtool unnecessarily takes
> device out of RPM suspend").
>
> There are a couple subtleties:
>
> - Prior to 3ef672ab1862, the device was resumed only for the duration of
> a single ethtool callback. 3ef672ab1862 changed e1000_set_phys_id() so
> the device was resumed for ETHTOOL_ID_ACTIVE and remained resumed until
> a subsequent callback for ETHTOOL_ID_INACTIVE. Preserve that part of
> 3ef672ab1862 so the device will not be runtime suspended while in the
> ETHTOOL_ID_ACTIVE state.
>
> - 3ef672ab1862 added "if (!pm_runtime_suspended())" in before reading the
> STATUS register in e1000_get_settings(). This was racy and is now
> unnecessary because dev_ethtool() has resumed the device already, so
> revert that.
>
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> ---
> drivers/net/ethernet/intel/e1000e/ethtool.c | 62 ++-------------------
> 1 file changed, 6 insertions(+), 56 deletions(-)

Tested-by: Naama Meir <naamax.meir@linux.intel.com>