linux-kernel - Re: [PATCH] hwmon/sch5627: Use common error handling code in sch5627

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Date:   Tue, 13 Mar 2018 09:00:47 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     Hans de Goede <hdegoede@...hat.com>
Cc:     SF Markus Elfring <elfring@...rs.sourceforge.net>,
        linux-hwmon@...r.kernel.org, Jean Delvare <jdelvare@...e.com>,
        LKML <linux-kernel@...r.kernel.org>,
        kernel-janitors@...r.kernel.org
Subject: Re: [PATCH] hwmon/sch5627: Use common error handling code in
 sch5627_probe()

On Tue, Mar 13, 2018 at 09:19:22AM +0100, Hans de Goede wrote:
> Hi,
> 
> On 12-03-18 22:23, SF Markus Elfring wrote:
> >From: Markus Elfring <elfring@...rs.sourceforge.net>
> >Date: Mon, 12 Mar 2018 22:15:59 +0100
> >
> >Adjust jump targets so that a bit of exception handling can be better
> >reused at the end of this function.
> >
> >This issue was detected by using the Coccinelle software.
> >
> >Signed-off-by: Markus Elfring <elfring@...rs.sourceforge.net>
> 
> So now we have a goto set_error_code with the code at the set_error_code
> doing something and then doing another goto. No, just no. goto-s going to
> a label calling another goto is completely unreadable.
> 
> I really do not see any reason for the proposed changes, they may remove
> a small amount of code duplication, but at a hugh cost wrt readability.
>
> TL;DR: NACK
> 
Fully agree. NACK confirmed.

Guenter

> Regards,
> 
> Hans
> 
> 
> 
> >---
> >  drivers/hwmon/sch5627.c | 60 ++++++++++++++++++++++++-------------------------
> >  1 file changed, 29 insertions(+), 31 deletions(-)
> >
> >diff --git a/drivers/hwmon/sch5627.c b/drivers/hwmon/sch5627.c
> >index 91544f2312e6..e7a2a974ab74 100644
> >--- a/drivers/hwmon/sch5627.c
> >+++ b/drivers/hwmon/sch5627.c
> >@@ -480,72 +480,64 @@ static int sch5627_probe(struct platform_device *pdev)
> >  	platform_set_drvdata(pdev, data);
> >  	val = sch56xx_read_virtual_reg(data->addr, SCH5627_REG_HWMON_ID);
> >-	if (val < 0) {
> >-		err = val;
> >-		goto error;
> >-	}
> >+	if (val < 0)
> >+		goto set_error_code;
> >+
> >  	if (val != SCH5627_HWMON_ID) {
> >  		pr_err("invalid %s id: 0x%02X (expected 0x%02X)\n", "hwmon",
> >  		       val, SCH5627_HWMON_ID);
> >-		err = -ENODEV;
> >-		goto error;
> >+		goto e_nodev;
> >  	}
> >  	val = sch56xx_read_virtual_reg(data->addr, SCH5627_REG_COMPANY_ID);
> >-	if (val < 0) {
> >-		err = val;
> >-		goto error;
> >-	}
> >+	if (val < 0)
> >+		goto set_error_code;
> >+
> >  	if (val != SCH5627_COMPANY_ID) {
> >  		pr_err("invalid %s id: 0x%02X (expected 0x%02X)\n", "company",
> >  		       val, SCH5627_COMPANY_ID);
> >-		err = -ENODEV;
> >-		goto error;
> >+		goto e_nodev;
> >  	}
> >  	val = sch56xx_read_virtual_reg(data->addr, SCH5627_REG_PRIMARY_ID);
> >-	if (val < 0) {
> >-		err = val;
> >-		goto error;
> >-	}
> >+	if (val < 0)
> >+		goto set_error_code;
> >+
> >  	if (val != SCH5627_PRIMARY_ID) {
> >  		pr_err("invalid %s id: 0x%02X (expected 0x%02X)\n", "primary",
> >  		       val, SCH5627_PRIMARY_ID);
> >-		err = -ENODEV;
> >-		goto error;
> >+		goto e_nodev;
> >  	}
> >  	build_code = sch56xx_read_virtual_reg(data->addr,
> >  					      SCH5627_REG_BUILD_CODE);
> >  	if (build_code < 0) {
> >  		err = build_code;
> >-		goto error;
> >+		goto remove_device;
> >  	}
> >  	build_id = sch56xx_read_virtual_reg16(data->addr,
> >  					      SCH5627_REG_BUILD_ID);
> >  	if (build_id < 0) {
> >  		err = build_id;
> >-		goto error;
> >+		goto remove_device;
> >  	}
> >  	hwmon_rev = sch56xx_read_virtual_reg(data->addr,
> >  					     SCH5627_REG_HWMON_REV);
> >  	if (hwmon_rev < 0) {
> >  		err = hwmon_rev;
> >-		goto error;
> >+		goto remove_device;
> >  	}
> >  	val = sch56xx_read_virtual_reg(data->addr, SCH5627_REG_CTRL);
> >-	if (val < 0) {
> >-		err = val;
> >-		goto error;
> >-	}
> >+	if (val < 0)
> >+		goto set_error_code;
> >+
> >  	data->control = val;
> >  	if (!(data->control & 0x01)) {
> >  		pr_err("hardware monitoring not enabled\n");
> >-		err = -ENODEV;
> >-		goto error;
> >+		goto e_nodev;
> >  	}
> >  	/* Trigger a Vbat voltage measurement, so that we get a valid reading
> >  	   the first time we read Vbat */
> >@@ -559,7 +551,7 @@ static int sch5627_probe(struct platform_device *pdev)
> >  	 */
> >  	err = sch5627_read_limits(data);
> >  	if (err)
> >-		goto error;
> >+		goto remove_device;
> >  	pr_info("found %s chip at %#hx\n", DEVNAME, data->addr);
> >  	pr_info("firmware build: code 0x%02X, id 0x%04X, hwmon: rev 0x%02X\n",
> >@@ -568,13 +560,13 @@ static int sch5627_probe(struct platform_device *pdev)
> >  	/* Register sysfs interface files */
> >  	err = sysfs_create_group(&pdev->dev.kobj, &sch5627_group);
> >  	if (err)
> >-		goto error;
> >+		goto remove_device;
> >  	data->hwmon_dev = hwmon_device_register(&pdev->dev);
> >  	if (IS_ERR(data->hwmon_dev)) {
> >  		err = PTR_ERR(data->hwmon_dev);
> >  		data->hwmon_dev = NULL;
> >-		goto error;
> >+		goto remove_device;
> >  	}
> >  	/* Note failing to register the watchdog is not a fatal error */
> >@@ -584,7 +576,13 @@ static int sch5627_probe(struct platform_device *pdev)
> >  	return 0;
> >-error:
> >+set_error_code:
> >+	err = val;
> >+	goto remove_device;
> >+
> >+e_nodev:
> >+	err = -ENODEV;
> >+remove_device:
> >  	sch5627_remove(pdev);
> >  	return err;
> >  }
> >