hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Third Round of Renesas ARM Based SoC Fixes for v4.13 

Fix deadlock in regulator quirk for R-Car Gen 2 SoCs
 
 The da9063/da9210 regulator quirk for R-Car Gen2 boards uses a bus
 notifier, and unregisters the notifier when it is no longer needed.
 However, a notifier must not be unregistered from within the call chain.
 
 This bug went unnoticed, as blocking_notifier_chain_unregister() didn't
 take the semaphore during early boot. This is no longer the case as of
 upstream commit 1c3c5eab17 ("sched/core: Enable might_sleep() and
 smp_processor_id() checks early") and a deadlock occurs.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJZfw75AAoJENfPZGlqN0++i24P/j38Z5LKt529CBT2uPgdiIr7
 lWEzU3Dgij/vPBUevz1s+hPa2i4jH1sfeKjSd2Ild3Ac+qAy6AwnzWlVYBCaBhlJ
 qFAsr3nZ6ybftdA4rIJb1pWF+ugG7uNcQ3S0J5vLeiRU5HC/ZR+Ar+hjeuDwwIGa
 889tI5UpKDFxYzkLIDVyiW0gX7WFhmxML0jptuV6c7bSl4Td/RxaP25Hcq8MsApv
 oVre7mWPBKrIrjH26lPIUmdN4SGIHgUS3k2j9fFoWit9p2gYX6WDVbHjgALzPL1r
 2Su8mSuP6ijutrrOuoB3OaNRlTaSr1Jpzfb6m6xRY+y1Anks0FxRVd712HrxinZK
 4xW0ebUpfxpFsg8lJGoe1d1FGOSuj6A3/5GCrA+fQS0LSKthft+ovHmKBAogbSm3
 7uCCU/h05LIkW0kDZYNjUqPWi+FwHZ4nEZEJiXMBt5DOyWpF5oIjCFeHmyp8VruI
 xHZnq0pcck0Y+OSln2tiV43kw4QzK3BjTZZRc/IkVf19m24y+WJu9KfXTQhCDeLt
 g4/zjAZrZddVQPtUz0f1YC07gPTmxLQpQJqLZBNeaed2W8p+tmUWUuoILpjPjEqR
 Uu0EQE+t205YaxEz/ctYATdrpNOM5TWRhD+U25VTfhgxar3p9aC4GNVskL/fMGUy
 /wTWYp1KVlxYjaxi3aOP
 =N5ig
 -----END PGP SIGNATURE-----

Merge tag 'renesas-fixes3-for-v4.13' of https://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into fixes

Pull "Third Round of Renesas ARM Based SoC Fixes for v4.13" from Simon Horman:

Fix deadlock in regulator quirk for R-Car Gen 2 SoCs

The da9063/da9210 regulator quirk for R-Car Gen2 boards uses a bus
notifier, and unregisters the notifier when it is no longer needed.
However, a notifier must not be unregistered from within the call chain.

This bug went unnoticed, as blocking_notifier_chain_unregister() didn't
take the semaphore during early boot. This is no longer the case as of
upstream commit 1c3c5eab17 ("sched/core: Enable might_sleep() and
smp_processor_id() checks early") and a deadlock occurs.

* tag 'renesas-fixes3-for-v4.13' of https://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  ARM: shmobile: rcar-gen2: Fix deadlock in regulator quirk
This commit is contained in:
Arnd Bergmann 2017-08-04 12:54:41 +02:00
parent 48cb953e6d fce8dc5e50
commit 264e22afa3
1 changed files with 5 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c
View File

@ -67,8 +67,12 @@ static int regulator_quirk_notify(struct notifier_block *nb,
{
struct device *dev = data;
struct i2c_client *client;
static bool done;
u32 mon;
if (done)
return 0;
mon = ioread32(irqc + IRQC_MONITOR);
dev_dbg(dev, "%s: %ld, IRQC_MONITOR = 0x%x\n", __func__, action, mon);
if (mon & REGULATOR_IRQ_MASK)
@ -99,7 +103,7 @@ static int regulator_quirk_notify(struct notifier_block *nb,
remove:
dev_info(dev, "IRQ2 is not asserted, removing quirk\n");
bus_unregister_notifier(&i2c_bus_type, nb);
done = true;
iounmap(irqc);
return 0;
}