| From foo@baz Sun Nov 19 11:32:28 CET 2017 |
| From: Fabien Lahoudere <fabien.lahoudere@collabora.co.uk> |
| Date: Tue, 20 Dec 2016 09:42:44 +0100 |
| Subject: rtc: rx8010: change lock mechanism |
| |
| From: Fabien Lahoudere <fabien.lahoudere@collabora.co.uk> |
| |
| |
| [ Upstream commit 666b5d1e9f8762300a410f9548b6e370d71dd382 ] |
| |
| Remove spinlock and use the "rtc->ops_lock" from RTC subsystem instead. |
| spin_lock_irqsave() is not needed here because we do not have hard IRQs. |
| |
| This patch fixes the following issue: |
| |
| root@GE004097290448 b850v3:~# hwclock --systohc |
| root@GE004097290448 b850v3:~# hwclock --systohc |
| root@GE004097290448 b850v3:~# hwclock --systohc |
| root@GE004097290448 b850v3:~# hwclock --systohc |
| root@GE004097290448 b850v3:~# hwclock --systohc |
| [ 82.108175] BUG: spinlock wrong CPU on CPU#0, hwclock/855 |
| [ 82.113660] lock: 0xedb4899c, .magic: dead4ead, .owner: hwclock/855, .owner_cpu: 1 |
| [ 82.121329] CPU: 0 PID: 855 Comm: hwclock Not tainted 4.8.0-00042-g09d5410-dirty #20 |
| [ 82.129078] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) |
| [ 82.135609] Backtrace: |
| [ 82.138090] [<8010d378>] (dump_backtrace) from [<8010d5c0>] (show_stack+0x20/0x24) |
| [ 82.145664] r7:ec936000 r6:600a0013 r5:00000000 r4:81031680 |
| [ 82.151402] [<8010d5a0>] (show_stack) from [<80401518>] (dump_stack+0xb4/0xe8) |
| [ 82.158636] [<80401464>] (dump_stack) from [<8017b8b0>] (spin_dump+0x84/0xcc) |
| [ 82.165775] r10:00000000 r9:ec936000 r8:81056090 r7:600a0013 r6:edb4899c r5:edb4899c |
| [ 82.173691] r4:e5033e00 r3:00000000 |
| [ 82.177308] [<8017b82c>] (spin_dump) from [<8017bcb0>] (do_raw_spin_unlock+0x108/0x130) |
| [ 82.185314] r5:edb4899c r4:edb4899c |
| [ 82.188938] [<8017bba8>] (do_raw_spin_unlock) from [<8094b93c>] (_raw_spin_unlock_irqrestore+0x34/0x54) |
| [ 82.198333] r5:edb4899c r4:600a0013 |
| [ 82.201953] [<8094b908>] (_raw_spin_unlock_irqrestore) from [<8065b090>] (rx8010_set_time+0x14c/0x188) |
| [ 82.211261] r5:00000020 r4:edb48990 |
| [ 82.214882] [<8065af44>] (rx8010_set_time) from [<80653fe4>] (rtc_set_time+0x70/0x104) |
| [ 82.222801] r7:00000051 r6:edb39da0 r5:edb39c00 r4:ec937e8c |
| [ 82.228535] [<80653f74>] (rtc_set_time) from [<80655774>] (rtc_dev_ioctl+0x3c4/0x674) |
| [ 82.236368] r7:00000051 r6:7ecf1b74 r5:00000000 r4:edb39c00 |
| [ 82.242106] [<806553b0>] (rtc_dev_ioctl) from [<80284034>] (do_vfs_ioctl+0xa4/0xa6c) |
| [ 82.249851] r8:00000003 r7:80284a40 r6:ed1e9c80 r5:edb44e60 r4:7ecf1b74 |
| [ 82.256642] [<80283f90>] (do_vfs_ioctl) from [<80284a40>] (SyS_ioctl+0x44/0x6c) |
| [ 82.263953] r10:00000000 r9:ec936000 r8:7ecf1b74 r7:4024700a r6:ed1e9c80 r5:00000003 |
| [ 82.271869] r4:ed1e9c80 |
| [ 82.274432] [<802849fc>] (SyS_ioctl) from [<80108520>] (ret_fast_syscall+0x0/0x1c) |
| [ 82.282005] r9:ec936000 r8:801086c4 r7:00000036 r6:00000000 r5:00000003 r4:0008e1bc |
| root@GE004097290448 b850v3:~# |
| Message from syslogd@GE004097290448 at Dec 3 11:17:08 ... |
| kernel:[ 82.108175] BUG: spinlock wrong CPU on CPU#0, hwclock/855 |
| |
| Message from syslogd@GE004097290448 at Dec 3 11:17:08 ... |
| kernel:[ 82.113660] lock: 0xedb4899c, .magic: dead4ead, .owner: hwclock/855, .owner_cpu: 1 |
| hwclock --systohc |
| root@GE004097290448 b850v3:~# |
| |
| Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.co.uk> |
| Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> |
| Signed-off-by: Sasha Levin <alexander.levin@verizon.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/rtc/rtc-rx8010.c | 24 +++--------------------- |
| 1 file changed, 3 insertions(+), 21 deletions(-) |
| |
| --- a/drivers/rtc/rtc-rx8010.c |
| +++ b/drivers/rtc/rtc-rx8010.c |
| @@ -63,7 +63,6 @@ struct rx8010_data { |
| struct i2c_client *client; |
| struct rtc_device *rtc; |
| u8 ctrlreg; |
| - spinlock_t flags_lock; |
| }; |
| |
| static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id) |
| @@ -72,12 +71,12 @@ static irqreturn_t rx8010_irq_1_handler( |
| struct rx8010_data *rx8010 = i2c_get_clientdata(client); |
| int flagreg; |
| |
| - spin_lock(&rx8010->flags_lock); |
| + mutex_lock(&rx8010->rtc->ops_lock); |
| |
| flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG); |
| |
| if (flagreg <= 0) { |
| - spin_unlock(&rx8010->flags_lock); |
| + mutex_unlock(&rx8010->rtc->ops_lock); |
| return IRQ_NONE; |
| } |
| |
| @@ -101,7 +100,7 @@ static irqreturn_t rx8010_irq_1_handler( |
| |
| i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg); |
| |
| - spin_unlock(&rx8010->flags_lock); |
| + mutex_unlock(&rx8010->rtc->ops_lock); |
| return IRQ_HANDLED; |
| } |
| |
| @@ -143,7 +142,6 @@ static int rx8010_set_time(struct device |
| u8 date[7]; |
| int ctrl, flagreg; |
| int ret; |
| - unsigned long irqflags; |
| |
| if ((dt->tm_year < 100) || (dt->tm_year > 199)) |
| return -EINVAL; |
| @@ -181,11 +179,8 @@ static int rx8010_set_time(struct device |
| if (ret < 0) |
| return ret; |
| |
| - spin_lock_irqsave(&rx8010->flags_lock, irqflags); |
| - |
| flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG); |
| if (flagreg < 0) { |
| - spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); |
| return flagreg; |
| } |
| |
| @@ -193,8 +188,6 @@ static int rx8010_set_time(struct device |
| ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, |
| flagreg & ~RX8010_FLAG_VLF); |
| |
| - spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); |
| - |
| return 0; |
| } |
| |
| @@ -288,12 +281,9 @@ static int rx8010_set_alarm(struct devic |
| u8 alarmvals[3]; |
| int extreg, flagreg; |
| int err; |
| - unsigned long irqflags; |
| |
| - spin_lock_irqsave(&rx8010->flags_lock, irqflags); |
| flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG); |
| if (flagreg < 0) { |
| - spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); |
| return flagreg; |
| } |
| |
| @@ -302,14 +292,12 @@ static int rx8010_set_alarm(struct devic |
| err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL, |
| rx8010->ctrlreg); |
| if (err < 0) { |
| - spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); |
| return err; |
| } |
| } |
| |
| flagreg &= ~RX8010_FLAG_AF; |
| err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg); |
| - spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); |
| if (err < 0) |
| return err; |
| |
| @@ -404,7 +392,6 @@ static int rx8010_ioctl(struct device *d |
| struct rx8010_data *rx8010 = dev_get_drvdata(dev); |
| int ret, tmp; |
| int flagreg; |
| - unsigned long irqflags; |
| |
| switch (cmd) { |
| case RTC_VL_READ: |
| @@ -419,16 +406,13 @@ static int rx8010_ioctl(struct device *d |
| return 0; |
| |
| case RTC_VL_CLR: |
| - spin_lock_irqsave(&rx8010->flags_lock, irqflags); |
| flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG); |
| if (flagreg < 0) { |
| - spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); |
| return flagreg; |
| } |
| |
| flagreg &= ~RX8010_FLAG_VLF; |
| ret = i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg); |
| - spin_unlock_irqrestore(&rx8010->flags_lock, irqflags); |
| if (ret < 0) |
| return ret; |
| |
| @@ -466,8 +450,6 @@ static int rx8010_probe(struct i2c_clien |
| rx8010->client = client; |
| i2c_set_clientdata(client, rx8010); |
| |
| - spin_lock_init(&rx8010->flags_lock); |
| - |
| err = rx8010_init_client(client); |
| if (err) |
| return err; |