The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d3b14296da69adb7825022f3224ac6137eb30abf Mon Sep 17 00:00:00 2001
From: Bartosz Golaszewski bgolaszewski@baylibre.com Date: Mon, 14 Sep 2020 17:45:48 +0200 Subject: [PATCH] rtc: rx8010: don't modify the global rtc ops
The way the driver is implemented is buggy for the (admittedly unlikely) use case where there are two RTCs with one having an interrupt configured and the second not. This is caused by the fact that we use a global rtc_class_ops struct which we modify depending on whether the irq number is present or not.
Fix it by using two const ops structs with and without alarm operations. While at it: not being able to request a configured interrupt is an error so don't ignore it and bail out of probe().
Fixes: ed13d89b08e3 ("rtc: Add Epson RX8010SJ RTC driver") Signed-off-by: Bartosz Golaszewski bgolaszewski@baylibre.com Signed-off-by: Alexandre Belloni alexandre.belloni@bootlin.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200914154601.32245-2-brgl@bgdev.pl
diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c index fe010151ec8f..08c93d492494 100644 --- a/drivers/rtc/rtc-rx8010.c +++ b/drivers/rtc/rtc-rx8010.c @@ -407,16 +407,26 @@ static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) } }
-static struct rtc_class_ops rx8010_rtc_ops = { +static const struct rtc_class_ops rx8010_rtc_ops_default = { .read_time = rx8010_get_time, .set_time = rx8010_set_time, .ioctl = rx8010_ioctl, };
+static const struct rtc_class_ops rx8010_rtc_ops_alarm = { + .read_time = rx8010_get_time, + .set_time = rx8010_set_time, + .ioctl = rx8010_ioctl, + .read_alarm = rx8010_read_alarm, + .set_alarm = rx8010_set_alarm, + .alarm_irq_enable = rx8010_alarm_irq_enable, +}; + static int rx8010_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct i2c_adapter *adapter = client->adapter; + const struct rtc_class_ops *rtc_ops; struct rx8010_data *rx8010; int err = 0;
@@ -447,16 +457,16 @@ static int rx8010_probe(struct i2c_client *client,
if (err) { dev_err(&client->dev, "unable to request IRQ\n"); - client->irq = 0; - } else { - rx8010_rtc_ops.read_alarm = rx8010_read_alarm; - rx8010_rtc_ops.set_alarm = rx8010_set_alarm; - rx8010_rtc_ops.alarm_irq_enable = rx8010_alarm_irq_enable; + return err; } + + rtc_ops = &rx8010_rtc_ops_alarm; + } else { + rtc_ops = &rx8010_rtc_ops_default; }
rx8010->rtc = devm_rtc_device_register(&client->dev, client->name, - &rx8010_rtc_ops, THIS_MODULE); + rtc_ops, THIS_MODULE);
if (IS_ERR(rx8010->rtc)) { dev_err(&client->dev, "unable to register the class device\n");