Re: [PATCH 4/6] soc: qcom: pmic_glink: Fix boot when QRTR=m

[Neil Armstrong <neil.armstrong@linaro.org>]

On 17/02/2024 16:02, Johan Hovold wrote:
> From: Rob Clark <robdclark@chromium.org>
> 
> We need to bail out before adding/removing devices if we are going to
> -EPROBE_DEFER. Otherwise boot can get stuck in a probe deferral loop due
> to a long-standing issue in driver core (see fbc35b45f9f6 ("Add
> documentation on meaning of -EPROBE_DEFER")).
> 
> Deregistering the altmode child device can potentially also trigger bugs
> in the DRM bridge implementation, which does not expect bridges to go
> away.
> 
> Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Rob Clark <robdclark@chromium.org>
> Link: https://lore.kernel.org/r/20231213210644.8702-1-robdclark@gmail.com
> [ johan: rebase on 6.8-rc4, amend commit message and mention DRM ]
> Fixes: 58ef4ece1e41 ("soc: qcom: pmic_glink: Introduce base PMIC GLINK driver")
> Cc: stable@vger.kernel.org      # 6.3
> Cc: Bjorn Andersson <andersson@kernel.org>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>   drivers/soc/qcom/pmic_glink.c | 21 +++++++++++----------
>   1 file changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/soc/qcom/pmic_glink.c b/drivers/soc/qcom/pmic_glink.c
> index f4bfd24386f1..f913e9bd57ed 100644
> --- a/drivers/soc/qcom/pmic_glink.c
> +++ b/drivers/soc/qcom/pmic_glink.c
> @@ -265,10 +265,17 @@ static int pmic_glink_probe(struct platform_device *pdev)
>   
>   	pg->client_mask = *match_data;
>   
> +	pg->pdr = pdr_handle_alloc(pmic_glink_pdr_callback, pg);
> +	if (IS_ERR(pg->pdr)) {
> +		ret = dev_err_probe(&pdev->dev, PTR_ERR(pg->pdr),
> +				    "failed to initialize pdr\n");
> +		return ret;
> +	}
> +
>   	if (pg->client_mask & BIT(PMIC_GLINK_CLIENT_UCSI)) {
>   		ret = pmic_glink_add_aux_device(pg, &pg->ucsi_aux, "ucsi");
>   		if (ret)
> -			return ret;
> +			goto out_release_pdr_handle;
>   	}
>   	if (pg->client_mask & BIT(PMIC_GLINK_CLIENT_ALTMODE)) {
>   		ret = pmic_glink_add_aux_device(pg, &pg->altmode_aux, "altmode");
> @@ -281,17 +288,11 @@ static int pmic_glink_probe(struct platform_device *pdev)
>   			goto out_release_altmode_aux;
>   	}
>   
> -	pg->pdr = pdr_handle_alloc(pmic_glink_pdr_callback, pg);
> -	if (IS_ERR(pg->pdr)) {
> -		ret = dev_err_probe(&pdev->dev, PTR_ERR(pg->pdr), "failed to initialize pdr\n");
> -		goto out_release_aux_devices;
> -	}
> -
>   	service = pdr_add_lookup(pg->pdr, "tms/servreg", "msm/adsp/charger_pd");
>   	if (IS_ERR(service)) {
>   		ret = dev_err_probe(&pdev->dev, PTR_ERR(service),
>   				    "failed adding pdr lookup for charger_pd\n");
> -		goto out_release_pdr_handle;
> +		goto out_release_aux_devices;
>   	}
>   
>   	mutex_lock(&__pmic_glink_lock);
> @@ -300,8 +301,6 @@ static int pmic_glink_probe(struct platform_device *pdev)
>   
>   	return 0;
>   
> -out_release_pdr_handle:
> -	pdr_handle_release(pg->pdr);
>   out_release_aux_devices:
>   	if (pg->client_mask & BIT(PMIC_GLINK_CLIENT_BATT))
>   		pmic_glink_del_aux_device(pg, &pg->ps_aux);
> @@ -311,6 +310,8 @@ static int pmic_glink_probe(struct platform_device *pdev)
>   out_release_ucsi_aux:
>   	if (pg->client_mask & BIT(PMIC_GLINK_CLIENT_UCSI))
>   		pmic_glink_del_aux_device(pg, &pg->ucsi_aux);
> +out_release_pdr_handle:
> +	pdr_handle_release(pg->pdr);
>   
>   	return ret;
>   }

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>