linux-kernel - Re: [PATCH] w1: omap-hdq: Simplify driver with PM runtime autosuspend

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Date:   Sun, 15 Dec 2019 19:16:37 -0800
From:   Tony Lindgren <tony@...mide.com>
To:     Andreas Kemnade <andreas@...nade.info>
Cc:     Evgeniy Polyakov <zbr@...emap.net>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-kernel@...r.kernel.org, linux-omap@...r.kernel.org,
        Adam Ford <aford173@...il.com>,
        "Andrew F . Davis" <afd@...com>,
        "H . Nikolaus Schaller" <hns@...delico.com>,
        Vignesh R <vigneshr@...com>
Subject: Re: [PATCH] w1: omap-hdq: Simplify driver with PM runtime autosuspend

* Tony Lindgren <tony@...mide.com> [191216 03:10]:
> Hi,
> 
> * Andreas Kemnade <andreas@...nade.info> [191215 22:04]:
> > On Sun, 15 Dec 2019 09:38:17 -0800
> > If I remember correctly this thing is critical to get the hwmod out of
> > reset but I need to examine that again:
> 
> Thanks for testing, yes that's what I thought might cause it
> too, but nope :)
> 
> We currently disable interrupts for some reason after
> the first read. That won't play with runtime PM autosuspend
> at all as we never enable them again until the device has
> idled. Can you try the following additional patch on top?

And we should probably do the following too to make sure
the mode is initialized before we call runtime PM.

Regards,

Tony

8< -------------------
diff --git a/drivers/w1/masters/omap_hdq.c b/drivers/w1/masters/omap_hdq.c
--- a/drivers/w1/masters/omap_hdq.c
+++ b/drivers/w1/masters/omap_hdq.c
@@ -565,6 +565,15 @@ static int omap_hdq_probe(struct platform_device *pdev)
 
 	mutex_init(&hdq_data->hdq_mutex);
 
+	ret = of_property_read_string(pdev->dev.of_node, "ti,mode", &mode);
+	if (ret < 0 || !strcmp(mode, "hdq")) {
+		hdq_data->mode = 0;
+		omap_w1_master.search = omap_w1_search_bus;
+	} else {
+		hdq_data->mode = 1;
+		omap_w1_master.triplet = omap_w1_triplet;
+	}
+
 	pm_runtime_enable(&pdev->dev);
 	pm_runtime_use_autosuspend(&pdev->dev);
 	pm_runtime_set_autosuspend_delay(&pdev->dev, 300);
@@ -599,15 +608,6 @@ static int omap_hdq_probe(struct platform_device *pdev)
 	pm_runtime_mark_last_busy(&pdev->dev);
 	pm_runtime_put_autosuspend(&pdev->dev);
 
-	ret = of_property_read_string(pdev->dev.of_node, "ti,mode", &mode);
-	if (ret < 0 || !strcmp(mode, "hdq")) {
-		hdq_data->mode = 0;
-		omap_w1_master.search = omap_w1_search_bus;
-	} else {
-		hdq_data->mode = 1;
-		omap_w1_master.triplet = omap_w1_triplet;
-	}
-
 	omap_w1_master.data = hdq_data;
 
 	ret = w1_add_master_device(&omap_w1_master);