[Intel-wired-lan] [PATCH v1 2/2] e1000e: Fixing packet loss issues on new platforms

[Mark Pearson]

Thanks Sasha,

Confirmed this fixes the problem on my X13 G2

Tested-by: Mark Pearson <markpearson at lenovo.com>

Mark

On 2021-09-22 09:29, Sasha Neftin wrote:
> 
> 
> 
> -------- Forwarded Message --------
> Subject: [PATCH v1 2/2] e1000e: Fixing packet loss issues on new platforms
> Date: Wed, 22 Sep 2021 09:55:42 +0300
> From: Sasha Neftin <sasha.neftin at intel.com>
> To: intel-wired-lan at lists.osuosl.org
> CC: Sasha Neftin <sasha.neftin at intel.com>
> 
> Update the HW MAC initialization flow. Do not gate DMA clock from
> the modPHY block. Keeping this clock will prevent drop packets sent
> in burst mode on the Kumeran interface.
> 
> Bugzilla: 
> https://apc01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.kernel.org%2Fshow_bug.cgi%3Fid%3D213651&data=04%7C01%7Cmarkpearson%40lenovo.com%7Cb5b073b630794c8ff7b908d97dcd03a3%7C5c7d0b28bdf8410caa934df372b16203%7C1%7C0%7C637679141742309105%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=1TJGrHWxUne7m%2BOPaAw5TuMAJHzOldg5Ws4xSY2Ew40%3D&reserved=0 
> 
> Bugzilla: 
> https://apc01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.kernel.org%2Fshow_bug.cgi%3Fid%3D213377&data=04%7C01%7Cmarkpearson%40lenovo.com%7Cb5b073b630794c8ff7b908d97dcd03a3%7C5c7d0b28bdf8410caa934df372b16203%7C1%7C0%7C637679141742319058%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=BRuJa4pf%2FhTau%2BfDY1lMOI%2F0wCMUYh5bB%2FJHZjTJmQw%3D&reserved=0 
> 
> Fixes: bc7f75fa9788 ("New pci-express e1000 driver");
> Signed-off-by: Sasha Neftin <sasha.neftin at intel.com>
> ---
>   drivers/net/ethernet/intel/e1000e/ich8lan.c | 11 ++++++++++-
>   drivers/net/ethernet/intel/e1000e/ich8lan.h |  3 +++
>   2 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c 
> b/drivers/net/ethernet/intel/e1000e/ich8lan.c
> index 66d7196310e2..5e4fc9b4e2ad 100644
> --- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
> +++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
> @@ -4813,7 +4813,7 @@ static s32 e1000_reset_hw_ich8lan(struct e1000_hw 
> *hw)
>   static s32 e1000_init_hw_ich8lan(struct e1000_hw *hw)
>   {
>       struct e1000_mac_info *mac = &hw->mac;
> -    u32 ctrl_ext, txdctl, snoop;
> +    u32 ctrl_ext, txdctl, snoop, fflt_dbg;
>       s32 ret_val;
>       u16 i;
>   @@ -4872,6 +4872,15 @@ static s32 e1000_init_hw_ich8lan(struct 
> e1000_hw *hw)
>           snoop = (u32)~(PCIE_NO_SNOOP_ALL);
>       e1000e_set_pcie_no_snoop(hw, snoop);
>   +    /* Enable workaround for packet loss issue on TGP PCH
> +     * Do not gate DMA clock from the modPHY block
> +     */
> +    if (mac->type >= e1000_pch_tgp) {
> +        fflt_dbg = er32(FFLT_DBG);
> +        fflt_dbg |= E1000_FFLT_DBG_DONT_GATE_WAKE_DMA_CLK;
> +        ew32(FFLT_DBG, fflt_dbg);
> +    }
> +
>       ctrl_ext = er32(CTRL_EXT);
>       ctrl_ext |= E1000_CTRL_EXT_RO_DIS;
>       ew32(CTRL_EXT, ctrl_ext);
> diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.h 
> b/drivers/net/ethernet/intel/e1000e/ich8lan.h
> index d6a092e5ee74..2504b11c3169 100644
> --- a/drivers/net/ethernet/intel/e1000e/ich8lan.h
> +++ b/drivers/net/ethernet/intel/e1000e/ich8lan.h
> @@ -289,6 +289,9 @@
>   /* Proprietary Latency Tolerance Reporting PCI Capability */
>   #define E1000_PCI_LTR_CAP_LPT        0xA8
>   +/* Don't gate wake DMA clock */
> +#define E1000_FFLT_DBG_DONT_GATE_WAKE_DMA_CLK    0x1000
> +
>   void e1000e_write_protect_nvm_ich8lan(struct e1000_hw *hw);
>   void e1000e_set_kmrn_lock_loss_workaround_ich8lan(struct e1000_hw *hw,
>                             bool state);