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authorBryan O'Donoghue <pure.logic@nexus-software.ie>2018-03-28 20:14:05 +0100
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2018-04-03 16:43:36 +0200
commit1485991c024603b2fb4ae77beb7a0d741128a48e (patch)
tree4baed7fc24f5ce718f918e9ae23bf5b919bdcd73
parent3fc990a5dbfff26fe2ef1286d9268d55a3136206 (diff)
downloadlinux-1485991c024603b2fb4ae77beb7a0d741128a48e.tar.bz2
rtc: snvs: Fix usage of snvs_rtc_enable
commit 179a502f8c46 ("rtc: snvs: add Freescale rtc-snvs driver") introduces the SNVS RTC driver with a function snvs_rtc_enable(). snvs_rtc_enable() can return an error on the enable path however this driver does not currently trap that failure on the probe() path and consequently if enabling the RTC fails we encounter a later error spinning forever in rtc_write_sync_lp(). [ 36.093481] [<c010d630>] (__irq_svc) from [<c0c2e9ec>] (_raw_spin_unlock_irqrestore+0x34/0x44) [ 36.102122] [<c0c2e9ec>] (_raw_spin_unlock_irqrestore) from [<c072e32c>] (regmap_read+0x4c/0x5c) [ 36.110938] [<c072e32c>] (regmap_read) from [<c085d0f4>] (rtc_write_sync_lp+0x6c/0x98) [ 36.118881] [<c085d0f4>] (rtc_write_sync_lp) from [<c085d160>] (snvs_rtc_alarm_irq_enable+0x40/0x4c) [ 36.128041] [<c085d160>] (snvs_rtc_alarm_irq_enable) from [<c08567b4>] (rtc_timer_do_work+0xd8/0x1a8) [ 36.137291] [<c08567b4>] (rtc_timer_do_work) from [<c01441b8>] (process_one_work+0x28c/0x76c) [ 36.145840] [<c01441b8>] (process_one_work) from [<c01446cc>] (worker_thread+0x34/0x58c) [ 36.153961] [<c01446cc>] (worker_thread) from [<c014aee4>] (kthread+0x138/0x150) [ 36.161388] [<c014aee4>] (kthread) from [<c0107e14>] (ret_from_fork+0x14/0x20) [ 36.168635] rcu_sched kthread starved for 2602 jiffies! g496 c495 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 [ 36.178564] rcu_sched R running task 0 8 2 0x00000000 [ 36.185664] [<c0c288b0>] (__schedule) from [<c0c29134>] (schedule+0x3c/0xa0) [ 36.192739] [<c0c29134>] (schedule) from [<c0c2db80>] (schedule_timeout+0x78/0x4e0) [ 36.200422] [<c0c2db80>] (schedule_timeout) from [<c01a7ab0>] (rcu_gp_kthread+0x648/0x1864) [ 36.208800] [<c01a7ab0>] (rcu_gp_kthread) from [<c014aee4>] (kthread+0x138/0x150) [ 36.216309] [<c014aee4>] (kthread) from [<c0107e14>] (ret_from_fork+0x14/0x20) This patch fixes by parsing the result of rtc_write_sync_lp() and propagating both in the probe and elsewhere. If the RTC doesn't start we don't proceed loading the driver and don't get into this loop mess later on. Fixes: 179a502f8c46 ("rtc: snvs: add Freescale rtc-snvs driver") Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
-rw-r--r--drivers/rtc/rtc-snvs.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c
index d8ef9e052c4f..9af591d5223c 100644
--- a/drivers/rtc/rtc-snvs.c
+++ b/drivers/rtc/rtc-snvs.c
@@ -132,20 +132,23 @@ static int snvs_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct snvs_rtc_data *data = dev_get_drvdata(dev);
unsigned long time;
+ int ret;
rtc_tm_to_time(tm, &time);
/* Disable RTC first */
- snvs_rtc_enable(data, false);
+ ret = snvs_rtc_enable(data, false);
+ if (ret)
+ return ret;
/* Write 32-bit time to 47-bit timer, leaving 15 LSBs blank */
regmap_write(data->regmap, data->offset + SNVS_LPSRTCLR, time << CNTR_TO_SECS_SH);
regmap_write(data->regmap, data->offset + SNVS_LPSRTCMR, time >> (32 - CNTR_TO_SECS_SH));
/* Enable RTC again */
- snvs_rtc_enable(data, true);
+ ret = snvs_rtc_enable(data, true);
- return 0;
+ return ret;
}
static int snvs_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
@@ -288,7 +291,11 @@ static int snvs_rtc_probe(struct platform_device *pdev)
regmap_write(data->regmap, data->offset + SNVS_LPSR, 0xffffffff);
/* Enable RTC */
- snvs_rtc_enable(data, true);
+ ret = snvs_rtc_enable(data, true);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to enable rtc %d\n", ret);
+ goto error_rtc_device_register;
+ }
device_init_wakeup(&pdev->dev, true);