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

[Neil Armstrong]

On 17/02/2024 16:02, Johan Hovold wrote:

From: Rob Clark <robdcl...@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.barysh...@linaro.org>
Signed-off-by: Rob Clark <robdcl...@chromium.org>
Link: https://lore.kernel.org/r/20231213210644.8702-1-robdcl...@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: sta...@vger.kernel.org      # 6.3
Cc: Bjorn Andersson <anders...@kernel.org>
Signed-off-by: Johan Hovold <johan+lin...@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.armstr...@linaro.org>