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authorGeert Uytterhoeven <geert+renesas@glider.be>2020-08-14 14:07:30 +0300
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2020-08-21 01:13:44 +0300
commitf65e727464d7c0090f05548e8f323779eaa97eda (patch)
tree6888ab3c2489bdb86fb23cdf8df2ec9e2cee891f /drivers/rtc
parentfc9656a370499e5a32425b715f8fed241e832458 (diff)
downloadlinux-f65e727464d7c0090f05548e8f323779eaa97eda.tar.xz
rtc: rtc-rs5c313: Fix late hardware init
rs5c313_rtc_init() calls platform_driver_register(), and initializes the hardware. This is wrong because of two reasons: 1. As soon as the driver has been registered, the device may be probed. If devm_rtc_device_register() is called before hardware initialization, reading the current time will fail: rs5c313 rs5c313: rs5c313_rtc_read_time: timeout error rs5c313 rs5c313: registered as rtc0 rs5c313 rs5c313: rs5c313_rtc_read_time: timeout error rs5c313 rs5c313: hctosys: unable to read the hardware clock 2. If the platform device does not exist, the driver will still write to a hardware device that may not be present. Fix this by moving the hardware initialization sequence to the driver's .probe() method. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20200814110731.29029-3-geert+renesas@glider.be
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-rs5c313.c20
1 files changed, 8 insertions, 12 deletions
diff --git a/drivers/rtc/rtc-rs5c313.c b/drivers/rtc/rtc-rs5c313.c
index 00b5ef753935..af72e428b218 100644
--- a/drivers/rtc/rtc-rs5c313.c
+++ b/drivers/rtc/rtc-rs5c313.c
@@ -366,8 +366,13 @@ static const struct rtc_class_ops rs5c313_rtc_ops = {
static int rs5c313_rtc_probe(struct platform_device *pdev)
{
- struct rtc_device *rtc = devm_rtc_device_register(&pdev->dev, "rs5c313",
- &rs5c313_rtc_ops, THIS_MODULE);
+ struct rtc_device *rtc;
+
+ rs5c313_init_port();
+ rs5c313_check_xstp_bit();
+
+ rtc = devm_rtc_device_register(&pdev->dev, "rs5c313", &rs5c313_rtc_ops,
+ THIS_MODULE);
return PTR_ERR_OR_ZERO(rtc);
}
@@ -381,16 +386,7 @@ static struct platform_driver rs5c313_rtc_platform_driver = {
static int __init rs5c313_rtc_init(void)
{
- int err;
-
- err = platform_driver_register(&rs5c313_rtc_platform_driver);
- if (err)
- return err;
-
- rs5c313_init_port();
- rs5c313_check_xstp_bit();
-
- return 0;
+ return platform_driver_register(&rs5c313_rtc_platform_driver);
}
static void __exit rs5c313_rtc_exit(void)