rtc-ds1742: fix races around device registration

* Call dev_set_drvdata before rtc device creation
* Use devres APIs and simplify error/remove path

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/rtc/rtc-ds1742.c b/drivers/rtc/rtc-ds1742.c
index 09249459e9a47b80192a113dd9cff5b845489564..19d2f3333cf0bb6dd81b7254468645422c636df7 100644 (file)
--- a/drivers/rtc/rtc-ds1742.c
+++ b/drivers/rtc/rtc-ds1742.c
@@ -21,7 +21,7 @@
 #include <linux/platform_device.h>
 #include <linux/io.h>
 
-#define DRV_VERSION "0.3"
+#define DRV_VERSION "0.4"
 
 #define RTC_SIZE               8
 
@@ -55,7 +55,6 @@ struct rtc_plat_data {
        void __iomem *ioaddr_rtc;
        size_t size_nvram;
        size_t size;
-       resource_size_t baseaddr;
        unsigned long last_jiffies;
        struct bin_attribute nvram_attr;
 };
@@ -163,27 +162,24 @@ static int __devinit ds1742_rtc_probe(struct platform_device *pdev)
        struct rtc_device *rtc;
        struct resource *res;
        unsigned int cen, sec;
-       struct rtc_plat_data *pdata = NULL;
-       void __iomem *ioaddr = NULL;
+       struct rtc_plat_data *pdata;
+       void __iomem *ioaddr;
        int ret = 0;
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res)
                return -ENODEV;
-       pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+       pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return -ENOMEM;
        pdata->size = res->end - res->start + 1;
-       if (!request_mem_region(res->start, pdata->size, pdev->name)) {
-               ret = -EBUSY;
-               goto out;
-       }
-       pdata->baseaddr = res->start;
-       ioaddr = ioremap(pdata->baseaddr, pdata->size);
-       if (!ioaddr) {
-               ret = -ENOMEM;
-               goto out;
-       }
+       if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size,
+               pdev->name))
+               return -EBUSY;
+       ioaddr = devm_ioremap(&pdev->dev, res->start, pdata->size);
+       if (!ioaddr)
+               return -ENOMEM;
+
        pdata->ioaddr_nvram = ioaddr;
        pdata->size_nvram = pdata->size - RTC_SIZE;
        pdata->ioaddr_rtc = ioaddr + pdata->size_nvram;
@@ -207,31 +203,19 @@ static int __devinit ds1742_rtc_probe(struct platform_device *pdev)
        if (!(readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG))
                dev_warn(&pdev->dev, "voltage-low detected.\n");
 
+       pdata->last_jiffies = jiffies;
+       platform_set_drvdata(pdev, pdata);
        rtc = rtc_device_register(pdev->name, &pdev->dev,
                                  &ds1742_rtc_ops, THIS_MODULE);
-       if (IS_ERR(rtc)) {
-               ret = PTR_ERR(rtc);
-               goto out;
-       }
+       if (IS_ERR(rtc))
+               return PTR_ERR(rtc);
        pdata->rtc = rtc;
-       pdata->last_jiffies = jiffies;
-       platform_set_drvdata(pdev, pdata);
 
        ret = sysfs_create_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
        if (ret) {
                dev_err(&pdev->dev, "creating nvram file in sysfs failed\n");
-               goto out;
+               rtc_device_unregister(rtc);
        }
-
-       return 0;
- out:
-       if (pdata->rtc)
-               rtc_device_unregister(pdata->rtc);
-       if (pdata->ioaddr_nvram)
-               iounmap(pdata->ioaddr_nvram);
-       if (pdata->baseaddr)
-               release_mem_region(pdata->baseaddr, pdata->size);
-       kfree(pdata);
        return ret;
 }
 
@@ -241,9 +225,6 @@ static int __devexit ds1742_rtc_remove(struct platform_device *pdev)
 
        sysfs_remove_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
        rtc_device_unregister(pdata->rtc);
-       iounmap(pdata->ioaddr_nvram);
-       release_mem_region(pdata->baseaddr, pdata->size);
-       kfree(pdata);
        return 0;
 }