[PATCH] drm/bridge: ti-sn65dsi86: Associate PWM device to auxiliary device

[Nikita Travkin]

Uwe Kleine-König писал(а) 27.11.2023 15:15:
> It's the ti_sn65dsi86.pwm auxiliary driver that creates the pwmchip, so
> let the auxiliary device be the parent of the pwm device.
> 
> Note that getting a reference to the ti-sn65dsi86's pwm using pwm_get()
> isn't affected by this change as ti_sn65dsi86_add_aux_device() sets the
> auxiliary device's of_node to that of the main device.
> 
> Also change PM runtime tracking and diagnostic messages to use that one.
> As the PM runtime functions also handle parent devices this should work
> fine, too.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
> ---
> Hello,
> 
> this patch has an (easy to resolve) conflict with a patch I sent earlier
> "drm/bridge: ti-sn65dsi86: Simplify using pm_runtime_resume_and_get()"
> (https://lore.kernel.org/dri-devel/20231123175425.496956-2-u.kleine-koenig@pengutronix.de).
> I was unsure if I should base this new patch on that older one.
> 
> While I think the patch is fine, I'd have a better feeling about it if
> someone could give feedback that the PWM still works as intended with
> this change.
> 

Hi, with this patch applied, pwm backlight fails to
probe on sc7180-acer-aspire1:

[    0.377853] pwm-backlight backlight: failed to apply initial PWM state: -13
[    0.378349] pwm-backlight: probe of backlight failed with error -13

Seems like the pwmchip device should get runtime_pm enabled?
The following patch seem to fix it.

Nikita


diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
index 254f0039dad2..b6813f9f6a8f 100644
--- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
@@ -1593,6 +1593,8 @@ static int ti_sn_pwm_probe(struct auxiliary_device *adev,
 	pdata->pchip.of_xlate = of_pwm_single_xlate;
 	pdata->pchip.of_pwm_n_cells = 1;
 
+	pm_runtime_enable(&adev->dev);
+
 	return pwmchip_add(&pdata->pchip);
 }