| Message ID | 1458826413-3916-1-git-send-email-alexander.stein@systec-electronic.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Alexander, On 2016-03-24 06:33, Alexander Stein wrote: > Using REGCACHE_RBTREE for MMIO regmap is not valid as spinlock's will be > used during cache allocation. > > This fixes the following bug: > BUG: sleeping function called from invalid context at mm/slab.h:388 > in_atomic(): 1, irqs_disabled(): 128, pid: 192, name: udevd > [...] > > Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> > --- > Please refer also to the discussion at > https://lists.freedesktop.org/archives/dri-devel/2016-January/098696.html > > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c > index e8d9337..ea65140 100644 > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c > @@ -40,7 +40,7 @@ static const struct regmap_config fsl_dcu_regmap_config = { > .reg_bits = 32, > .reg_stride = 4, > .val_bits = 32, > - .cache_type = REGCACHE_RBTREE, > + .cache_type = REGCACHE_FLAT, To use flat regcache you also need to set the max_register. I already have such a patch, see: https://lists.freedesktop.org/archives/dri-devel/2016-January/099121.html However, the current suspend/resume implementation (which uses the regcache) is anyway flawed. I currently prepare a patchset to remove the regmap cache entirely and use Thierry's new generic suspend/resume functions. -- Stefan > > .volatile_reg = fsl_dcu_drm_is_volatile_reg, > };
On Friday 25 March 2016 09:24:28, Stefan Agner wrote: > Hi Alexander, > > On 2016-03-24 06:33, Alexander Stein wrote: > > Using REGCACHE_RBTREE for MMIO regmap is not valid as spinlock's will be > > used during cache allocation. > > > > This fixes the following bug: > > BUG: sleeping function called from invalid context at mm/slab.h:388 > > in_atomic(): 1, irqs_disabled(): 128, pid: 192, name: udevd > > [...] > > > > Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> > > --- > > Please refer also to the discussion at > > https://lists.freedesktop.org/archives/dri-devel/2016-January/098696.html > > > > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c > > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c > > index e8d9337..ea65140 100644 > > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c > > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c > > @@ -40,7 +40,7 @@ static const struct regmap_config fsl_dcu_regmap_config > > = {> > > .reg_bits = 32, > > .reg_stride = 4, > > .val_bits = 32, > > > > - .cache_type = REGCACHE_RBTREE, > > + .cache_type = REGCACHE_FLAT, > > To use flat regcache you also need to set the max_register. Ah, thanks for that hint, I was not aware of that. I wondered why my kernel crashed using flat cache. Seems cache allocation is too small when max_register=0. Just sent a patch enforcing setting max_register. > I already have such a patch, see: > https://lists.freedesktop.org/archives/dri-devel/2016-January/099121.html Thanks, meanwhile this will do for me. I think. > However, the current suspend/resume implementation (which uses the > regcache) is anyway flawed. I currently prepare a patchset to remove the > regmap cache entirely and use Thierry's new generic suspend/resume > functions. Feel free to cc me. Best regards, Alexander
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c index e8d9337..ea65140 100644 --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c @@ -40,7 +40,7 @@ static const struct regmap_config fsl_dcu_regmap_config = { .reg_bits = 32, .reg_stride = 4, .val_bits = 32, - .cache_type = REGCACHE_RBTREE, + .cache_type = REGCACHE_FLAT, .volatile_reg = fsl_dcu_drm_is_volatile_reg, };
Using REGCACHE_RBTREE for MMIO regmap is not valid as spinlock's will be used during cache allocation. This fixes the following bug: BUG: sleeping function called from invalid context at mm/slab.h:388 in_atomic(): 1, irqs_disabled(): 128, pid: 192, name: udevd [...] Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> --- Please refer also to the discussion at https://lists.freedesktop.org/archives/dri-devel/2016-January/098696.html drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)