diff options
| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2020-08-14 14:07:30 +0300 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2020-08-21 01:13:44 +0300 |
| commit | f65e727464d7c0090f05548e8f323779eaa97eda (patch) | |
| tree | 6888ab3c2489bdb86fb23cdf8df2ec9e2cee891f /drivers/rtc | |
| parent | fc9656a370499e5a32425b715f8fed241e832458 (diff) | |
| download | linux-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.c | 20 |
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) |