[PATCH] mt76: mt7921e: fix reset failure in mt7921_pci_probe

[Sean Wang]

@nbd please drop the patch, I will post a new one to fix the aspm issue

On Thu, Jan 6, 2022 at 1:32 PM <sean.wang at mediatek.com> wrote:
>
> From: Deren Wu <deren.wu at mediatek.com>
>
> Ensure that the device returns to the driver's own state to switch ASPM
> into the active state before we start resetting the device to fix
> the following kernel panic.
>
> [   17.164952]  dump_stack_lvl+0x48/0x5e
> [   17.164955]  bad_page.cold+0x63/0x94
> [   17.164957]  free_pcppages_bulk+0x1f2/0x360
> [   17.164961]  free_unref_page+0xb4/0x120
> [   17.164963]  mt76_dma_rx_cleanup+0x94/0x110 [mt76]
> [   17.164969]  mt7921_wpdma_reset+0xbc/0x1c0 [mt7921e]
> [   17.164972]  mt7921_register_device+0x32b/0x5d0 [mt7921_common]
> [   17.164976]  mt7921_pci_probe+0x1d5/0x210 [mt7921e]
> [   17.164977]  ? __pm_runtime_resume+0x58/0x80
> [   17.164979]  local_pci_probe+0x45/0x80
> [   17.164981]  ? pci_match_device+0xac/0x130
> [   17.164983]  pci_device_probe+0xd2/0x1c0
> [   17.164984]  really_probe+0x1f5/0x3f0
> [   17.164987]  __driver_probe_device+0xfe/0x180
> [   17.164988]  driver_probe_device+0x1e/0x90
> [   17.164990]  __driver_attach+0xc0/0x1c0
> [   17.164991]  ? __device_attach_driver+0xe0/0xe0
> [   17.164992]  ? __device_attach_driver+0xe0/0xe0
> [   17.164994]  bus_for_each_dev+0x78/0xc0
> [   17.164995]  new_id_store+0xfc/0x1d0
> [   17.164996]  kernfs_fop_write_iter+0x11c/0x1b0
> [   17.164998]  new_sync_write+0x11f/0x1b0
> [   17.165001]  vfs_write+0x209/0x2a0
> [   17.165003]  ksys_write+0x5f/0xe0
> [   17.165004]  do_syscall_64+0x3b/0xc0
> [   17.165006]
>
> Fixes: bf3747ae2e25 ("mt76: mt7921: enable aspm by default")
> Reported-by: Kai-Chuan Hsieh <kaichuan.hsieh at canonical.com>
> Co-developed-by: Sean Wang <sean.wang at mediatek.com>
> Signed-off-by: Sean Wang <sean.wang at mediatek.com>
> Signed-off-by: Deren Wu <deren.wu at mediatek.com>
> ---
>  .../net/wireless/mediatek/mt76/mt7921/dma.c    |  4 ++++
>  .../net/wireless/mediatek/mt76/mt7921/mt7921.h |  1 +
>  .../wireless/mediatek/mt76/mt7921/pci_mcu.c    | 18 ++++++++++++++----
>  3 files changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/dma.c b/drivers/net/wireless/mediatek/mt76/mt7921/dma.c
> index cdff1fd52d93..0c4b0e0e634a 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7921/dma.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7921/dma.c
> @@ -364,6 +364,10 @@ int mt7921_dma_init(struct mt7921_dev *dev)
>         if (ret)
>                 return ret;
>
> +       ret = __mt7921e_mcu_drv_pmctrl(dev);
> +       if (ret)
> +               return ret;
> +
>         ret = mt7921_wfsys_reset(dev);
>         if (ret)
>                 return ret;
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h b/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h
> index 8b674e042568..63e3c7ef5e89 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h
> +++ b/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h
> @@ -443,6 +443,7 @@ int mt7921e_mcu_init(struct mt7921_dev *dev);
>  int mt7921s_wfsys_reset(struct mt7921_dev *dev);
>  int mt7921s_mac_reset(struct mt7921_dev *dev);
>  int mt7921s_init_reset(struct mt7921_dev *dev);
> +int __mt7921e_mcu_drv_pmctrl(struct mt7921_dev *dev);
>  int mt7921e_mcu_drv_pmctrl(struct mt7921_dev *dev);
>  int mt7921e_mcu_fw_pmctrl(struct mt7921_dev *dev);
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/pci_mcu.c b/drivers/net/wireless/mediatek/mt76/mt7921/pci_mcu.c
> index f9e350b67fdc..36669e5aeef3 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7921/pci_mcu.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7921/pci_mcu.c
> @@ -59,10 +59,8 @@ int mt7921e_mcu_init(struct mt7921_dev *dev)
>         return err;
>  }
>
> -int mt7921e_mcu_drv_pmctrl(struct mt7921_dev *dev)
> +int __mt7921e_mcu_drv_pmctrl(struct mt7921_dev *dev)
>  {
> -       struct mt76_phy *mphy = &dev->mt76.phy;
> -       struct mt76_connac_pm *pm = &dev->pm;
>         int i, err = 0;
>
>         for (i = 0; i < MT7921_DRV_OWN_RETRY_COUNT; i++) {
> @@ -75,9 +73,21 @@ int mt7921e_mcu_drv_pmctrl(struct mt7921_dev *dev)
>         if (i == MT7921_DRV_OWN_RETRY_COUNT) {
>                 dev_err(dev->mt76.dev, "driver own failed\n");
>                 err = -EIO;
> -               goto out;
>         }
>
> +       return err;
> +}
> +
> +int mt7921e_mcu_drv_pmctrl(struct mt7921_dev *dev)
> +{
> +       struct mt76_phy *mphy = &dev->mt76.phy;
> +       struct mt76_connac_pm *pm = &dev->pm;
> +       int err;
> +
> +       err = __mt7921e_mcu_drv_pmctrl(dev);
> +       if (err < 0)
> +               goto out;
> +
>         mt7921_wpdma_reinit_cond(dev);
>         clear_bit(MT76_STATE_PM, &mphy->state);
>
> --
> 2.25.1
>