Re: [Intel-wired-lan] [PATCH iwl-net v1 1/1] e1000e: change usleep_range to udelay in PHY mdic access

["Ruinskiy, Dima" <dima.ruinskiy@intel.com>]

On 17/04/2024 22:03, Lifshits, Vitaly wrote:
> This is a partial revert of commit 6dbdd4de0362 ("e1000e: Workaround
> for sporadic MDI error on Meteor Lake systems"). The referenced commit
> introduced an issue on vPro systems, where disconnecting and reconnecting
> the LAN cable might result in a kernel panic.
> 
> This was root caused to the usage of usleep_range in an atomic content
> while trying to access the PHY. Change back the usleep_range calls to
> udelay.
> 
> Fixes: 6dbdd4de0362 ("e1000e: Workaround for sporadic MDI error on Meteor Lake systems")
> Co-developed-by: Sasha Neftin <sasha.neftin@intel.com>
> Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
> Signed-off-by: Vitaly Lifshits <vitaly.lifshits@intel.com>
> ---
>   drivers/net/ethernet/intel/e1000e/phy.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/e1000e/phy.c b/drivers/net/ethernet/intel/e1000e/phy.c
> index 93544f1cc2a5..f7ae0e0aa4a4 100644
> --- a/drivers/net/ethernet/intel/e1000e/phy.c
> +++ b/drivers/net/ethernet/intel/e1000e/phy.c
> @@ -157,7 +157,7 @@ s32 e1000e_read_phy_reg_mdic(struct e1000_hw *hw, u32 offset, u16 *data)
>                   * the lower time out
>                   */
>                  for (i = 0; i < (E1000_GEN_POLL_TIMEOUT * 3); i++) {
> -                       usleep_range(50, 60);
> +                       udelay(50);
>                          mdic = er32(MDIC);
>                          if (mdic & E1000_MDIC_READY)
>                                  break;
> @@ -181,7 +181,7 @@ s32 e1000e_read_phy_reg_mdic(struct e1000_hw *hw, u32 offset, u16 *data)
>                   * reading duplicate data in the next MDIC transaction.
>                   */
>                  if (hw->mac.type == e1000_pch2lan)
> -                       usleep_range(100, 150);
> +                       udelay(100);
> 
>                  if (success) {
>                          *data = (u16)mdic;
> @@ -237,7 +237,7 @@ s32 e1000e_write_phy_reg_mdic(struct e1000_hw *hw, u32 offset, u16 data)
>                   * the lower time out
>                   */
>                  for (i = 0; i < (E1000_GEN_POLL_TIMEOUT * 3); i++) {
> -                       usleep_range(50, 60);
> +                       udelay(50);
>                          mdic = er32(MDIC);
>                          if (mdic & E1000_MDIC_READY)
>                                  break;
> @@ -261,7 +261,7 @@ s32 e1000e_write_phy_reg_mdic(struct e1000_hw *hw, u32 offset, u16 data)
>                   * reading duplicate data in the next MDIC transaction.
>                   */
>                  if (hw->mac.type == e1000_pch2lan)
> -                       usleep_range(100, 150);
> +                       udelay(100);
> 
>                  if (success)
>                          return 0;
> --
> 2.34.1
> 

Tested-by: Dima Ruinskiy <dima.ruinskiy@intel.com>