target/linux/ipq806x/patches-5.10/108-v5.14-net-stmmac-explicitly-deassert-gmac-ahb-reset.patch

   1 From e67f325e9cd67562b761e884680c0fec03a6f404 Mon Sep 17 00:00:00 2001
   2 From: Matthew Hagan <mnhagan88@gmail.com>
   3 Date: Tue, 8 Jun 2021 19:59:06 +0100
   4 Subject: net: stmmac: explicitly deassert GMAC_AHB_RESET
   5
   6 We are currently assuming that GMAC_AHB_RESET will already be deasserted
   7 by the bootloader. However if this has not been done, probing of the GMAC
   8 will fail. To remedy this we must ensure GMAC_AHB_RESET has been deasserted
   9 prior to probing.
  10
  11 v2 changes:
  12  - remove NULL condition check for stmmac_ahb_rst in stmmac_main.c
  13  - unwrap dev_err() message in stmmac_main.c
  14  - add PTR_ERR() around plat->stmmac_ahb_rst in stmmac_platform.c
  15
  16 v3 changes:
  17  - add error pointer to dev_err() output
  18  - add reset_control_assert(stmmac_ahb_rst) in stmmac_dvr_remove
  19  - revert PTR_ERR() around plat->stmmac_ahb_rst since this is performed
  20    on the returned value of ret by the calling function
  21
  22 Signed-off-by: Matthew Hagan <mnhagan88@gmail.com>
  23 Signed-off-by: David S. Miller <davem@davemloft.net>
  24 ---
  25  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c     | 5 +++++
  26  drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 6 ++++++
  27  include/linux/stmmac.h                                | 1 +
  28  3 files changed, 12 insertions(+)
  29
  30 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
  31 +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
  32 @@ -5023,6 +5023,10 @@ int stmmac_dvr_probe(struct device *devi
  33                         reset_control_reset(priv->plat->stmmac_rst);
  34         }
  35
  36 +       ret = reset_control_deassert(priv->plat->stmmac_ahb_rst);
  37 +       if (ret == -ENOTSUPP)
  38 +               dev_err(priv->device, "unable to bring out of ahb reset\n");
  39 +
  40         /* Init MAC and get the capabilities */
  41         ret = stmmac_hw_init(priv);
  42         if (ret)
  43 @@ -5247,6 +5251,7 @@ int stmmac_dvr_remove(struct device *dev
  44         phylink_destroy(priv->phylink);
  45         if (priv->plat->stmmac_rst)
  46                 reset_control_assert(priv->plat->stmmac_rst);
  47 +       reset_control_assert(priv->plat->stmmac_ahb_rst);
  48         pm_runtime_put(dev);
  49         pm_runtime_disable(dev);
  50         if (priv->hw->pcs != STMMAC_PCS_TBI &&
  51 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
  52 +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
  53 @@ -617,6 +617,12 @@ stmmac_probe_config_dt(struct platform_d
  54                 plat->stmmac_rst = NULL;
  55         }
  56
  57 +       plat->stmmac_ahb_rst = devm_reset_control_get_optional_shared(
  58 +                                                       &pdev->dev, "ahb");
  59 +       if (IS_ERR(plat->stmmac_ahb_rst))
  60 +               if (PTR_ERR(plat->stmmac_ahb_rst) == -EPROBE_DEFER)
  61 +                       goto error_hw_init;
  62 +
  63         return plat;
  64
  65  error_hw_init:
  66 --- a/include/linux/stmmac.h
  67 +++ b/include/linux/stmmac.h
  68 @@ -192,6 +192,7 @@ struct plat_stmmacenet_data {
  69         unsigned int clk_ref_rate;
  70         s32 ptp_max_adj;
  71         struct reset_control *stmmac_rst;
  72 +       struct reset_control *stmmac_ahb_rst;
  73         struct stmmac_axi *axi;
  74         int has_gmac4;
  75         bool has_sun8i;