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From: Alexandre Bailon <abailon@baylibre.com>
To: khilman@baylibre.com, david@lechnology.com, b-liu@ti.com,
	balbi@kernel.org
Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
	Alexandre Bailon <abailon@baylibre.com>
Subject: [PATCH v2 1/3] usb: musb: da8xx: Call earlier clk_prepare_enable()
Date: Wed, 26 Oct 2016 12:58:21 +0200	[thread overview]
Message-ID: <1477479503-5131-2-git-send-email-abailon@baylibre.com> (raw)
In-Reply-To: <1477479503-5131-1-git-send-email-abailon@baylibre.com>

The first attempt to read a register may fail because the clock may not
be enabled, and then the probe of musb driver will fail.
Call clk_prepare_enable() before the first register read.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
---
 drivers/usb/musb/da8xx.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/musb/da8xx.c b/drivers/usb/musb/da8xx.c
index 210b7e4..6749aa1 100644
--- a/drivers/usb/musb/da8xx.c
+++ b/drivers/usb/musb/da8xx.c
@@ -366,6 +366,12 @@ static int da8xx_musb_init(struct musb *musb)
 
 	musb->mregs += DA8XX_MENTOR_CORE_OFFSET;
 
+	ret = clk_prepare_enable(glue->clk);
+	if (ret) {
+		dev_err(glue->dev, "failed to enable clock\n");
+		return ret;
+	}
+
 	/* Returns zero if e.g. not clocked */
 	rev = musb_readl(reg_base, DA8XX_USB_REVISION_REG);
 	if (!rev)
@@ -377,12 +383,6 @@ static int da8xx_musb_init(struct musb *musb)
 		goto fail;
 	}
 
-	ret = clk_prepare_enable(glue->clk);
-	if (ret) {
-		dev_err(glue->dev, "failed to enable clock\n");
-		goto fail;
-	}
-
 	setup_timer(&otg_workaround, otg_timer, (unsigned long)musb);
 
 	/* Reset the controller */
@@ -392,7 +392,7 @@ static int da8xx_musb_init(struct musb *musb)
 	ret = phy_init(glue->phy);
 	if (ret) {
 		dev_err(glue->dev, "Failed to init phy.\n");
-		goto err_phy_init;
+		goto fail;
 	}
 
 	ret = phy_power_on(glue->phy);
@@ -412,9 +412,8 @@ static int da8xx_musb_init(struct musb *musb)
 
 err_phy_power_on:
 	phy_exit(glue->phy);
-err_phy_init:
-	clk_disable_unprepare(glue->clk);
 fail:
+	clk_disable_unprepare(glue->clk);
 	return ret;
 }
 
-- 
2.7.3

  reply	other threads:[~2016-10-26 10:59 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-26 10:58 [PATCH v2 0/3] usb: musb: da8xx: Fix few issues Alexandre Bailon
2016-10-26 10:58 ` Alexandre Bailon [this message]
2016-10-26 10:58 ` [PATCH v2 2/3] phy: da8xx-usb: Configure CFGCHIP2 to support OTG workaround Alexandre Bailon
2016-10-26 15:40   ` David Lechner
2016-10-26 16:43     ` Alexandre Bailon
2016-10-26 10:58 ` [PATCH v2 3/3] usb: musb: da8xx: Only execute the OTG workaround when phy in OTG mode Alexandre Bailon
2016-10-28  2:56   ` David Lechner
2016-10-28 12:39     ` Alexandre Bailon
2016-10-28 17:11       ` David Lechner
2016-10-29  3:11         ` Bin Liu
2016-10-27 17:16 ` [PATCH v2 0/3] usb: musb: da8xx: Fix few issues David Lechner
2016-10-27 18:44   ` David Lechner
2016-10-28  9:31     ` Alexandre Bailon
2016-10-28 10:16       ` Alexandre Bailon
2016-10-28 17:50       ` David Lechner

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