Lockdep warning when using REGCACHE_RBTREE

2016-01-15 Thread Mark Brown
On Thu, Jan 14, 2016 at 05:14:47PM -0800, Stefan Agner wrote: > On a slightly other topic, I question whether REGCACHE_RBTREE is the > right cache type for the DCU DRM driver. The driver has uses a regmap > area of 1144 32-bit registers, the most space is used by the layer > configuration

Lockdep warning when using REGCACHE_RBTREE

2016-01-15 Thread Mark Brown
On Fri, Jan 15, 2016 at 10:45:41AM +0100, Peter Zijlstra wrote: > So _regmap_write() does: map->lock(map->lock_arg) > Which isn't very enlightening, since that can be a mutex or a spinlock, > the above strongly suggests spinlock though. > Looking at __regmap_init(), this seems to depend on: >

Lockdep warning when using REGCACHE_RBTREE

2016-01-15 Thread Stefan Agner
On 2016-01-15 08:28, Mark Brown wrote: > On Thu, Jan 14, 2016 at 05:14:47PM -0800, Stefan Agner wrote: > >> On a slightly other topic, I question whether REGCACHE_RBTREE is the >> right cache type for the DCU DRM driver. The driver has uses a regmap >> area of 1144 32-bit registers, the most

Lockdep warning when using REGCACHE_RBTREE

2016-01-15 Thread Peter Zijlstra
On Thu, Jan 14, 2016 at 02:30:50PM -0800, Stefan Agner wrote: > Hi Mark, > > I currently work on the DCU DRM driver (drivers/gpu/drm/fsl-dcu/) on a > Linux 4.4 kernel. With CONFIG_LOCKDEP enabled I get the following > warning on startup: > > [1.327284] [ cut here ] >

Lockdep warning when using REGCACHE_RBTREE

2016-01-15 Thread Mark Brown
On Thu, Jan 14, 2016 at 02:30:50PM -0800, Stefan Agner wrote: > I currently work on the DCU DRM driver (drivers/gpu/drm/fsl-dcu/) on a > Linux 4.4 kernel. With CONFIG_LOCKDEP enabled I get the following > warning on startup: Please don't paste entire stack dumps into e-mail, they're completely

Lockdep warning when using REGCACHE_RBTREE

2016-01-14 Thread Stefan Agner
On 2016-01-14 16:01, Mark Brown wrote: > On Thu, Jan 14, 2016 at 02:30:50PM -0800, Stefan Agner wrote: > >> I currently work on the DCU DRM driver (drivers/gpu/drm/fsl-dcu/) on a >> Linux 4.4 kernel. With CONFIG_LOCKDEP enabled I get the following >> warning on startup: > > Please don't paste

Lockdep warning when using REGCACHE_RBTREE

2016-01-14 Thread Stefan Agner
Hi Mark, I currently work on the DCU DRM driver (drivers/gpu/drm/fsl-dcu/) on a Linux 4.4 kernel. With CONFIG_LOCKDEP enabled I get the following warning on startup: [1.327284] [ cut here ] [1.332010] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:2755