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

[Johan Hovold <johan+linaro@kernel.org>]

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;
 }
-- 
2.43.0