diff options
| author | Laurence de Bruxelles <lfdebrux@gmail.com> | 2022-01-01 18:41:49 +0300 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2022-01-05 03:05:17 +0300 |
| commit | 34127b3632b21e5c391756e724b1198eb9917981 (patch) | |
| tree | fa92a449dbde8b55d8bc20fb87297290a329e909 /drivers/rtc/rtc-pxa.c | |
| parent | 05020a733b02cf7a474305e620fb306cd3abfe84 (diff) | |
| download | linux-34127b3632b21e5c391756e724b1198eb9917981.tar.xz | |
rtc: pxa: fix null pointer dereference
With the latest stable kernel versions the rtc on the PXA based
Zaurus does not work, when booting I see the following kernel messages:
pxa-rtc pxa-rtc: failed to find rtc clock source
pxa-rtc pxa-rtc: Unable to init SA1100 RTC sub-device
pxa-rtc: probe of pxa-rtc failed with error -2
hctosys: unable to open rtc device (rtc0)
I think this is because commit f2997775b111 ("rtc: sa1100: fix possible
race condition") moved the allocation of the rtc_device struct out of
sa1100_rtc_init and into sa1100_rtc_probe. This means that pxa_rtc_probe
also needs to do allocation for the rtc_device struct, otherwise
sa1100_rtc_init will try to dereference a null pointer. This patch adds
that allocation by copying how sa1100_rtc_probe in
drivers/rtc/rtc-sa1100.c does it; after the IRQs are set up a managed
rtc_device is allocated.
I've tested this patch with `qemu-system-arm -machine akita` and with a
real Zaurus SL-C1000 applied to 4.19, 5.4, and 5.10.
Signed-off-by: Laurence de Bruxelles <lfdebrux@gmail.com>
Fixes: f2997775b111 ("rtc: sa1100: fix possible race condition")
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220101154149.12026-1-lfdebrux@gmail.com
Diffstat (limited to 'drivers/rtc/rtc-pxa.c')
| -rw-r--r-- | drivers/rtc/rtc-pxa.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pxa.c b/drivers/rtc/rtc-pxa.c index d2f1d8f754bf..cf8119b6d320 100644 --- a/drivers/rtc/rtc-pxa.c +++ b/drivers/rtc/rtc-pxa.c @@ -330,6 +330,10 @@ static int __init pxa_rtc_probe(struct platform_device *pdev) if (sa1100_rtc->irq_alarm < 0) return -ENXIO; + sa1100_rtc->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(sa1100_rtc->rtc)) + return PTR_ERR(sa1100_rtc->rtc); + pxa_rtc->base = devm_ioremap(dev, pxa_rtc->ress->start, resource_size(pxa_rtc->ress)); if (!pxa_rtc->base) { |