RE: [PATCH] drm/amdgpu: backlight rescaling to original range
[AMD Official Use Only - Internal Distribution Only]
Hello All,
Could you please provide your feedback for this patch?
Regards,
Ikshwaku
-Original Message-
From: Chauhan, Ikshwaku
Sent: Wednesday, June 17, 2020 3:20 AM
To: Wentland, Harry ; Li, Sun peng (Leo)
; Deucher, Alexander
Cc: amd-gfx@lists.freedesktop.org; Chauhan, Ikshwaku
Subject: [PATCH] drm/amdgpu: backlight rescaling to original range
[why]
The brightness input is in the range 0-255.It is getting scaled between the
requested min and max input signal and also scaled up by 0x101 to match the DC
interface which has a range of 0 to 0x. This scaled brightness value is not
rescaled back to original range(0-255) when we reads it back.It returns the
brightness value in the range of 0-65535 instead of 0-255.
[how]
Rescaled the brightness value form the scaled brightness range 0-65535 to input
brightness range 0-255.
Signed-off-by: Ikshwaku Chauhan
---
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 40 ++-
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 5 +++
2 files changed, 34 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 9ab0d8521576..73b0a084e893 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2881,7 +2881,8 @@ static int set_backlight_via_aux(struct dc_link *link,
uint32_t brightness) }
static u32 convert_brightness(const struct amdgpu_dm_backlight_caps *caps,
- const uint32_t user_brightness)
+ const uint32_t user_brightness,
+ enum convert_backlight flag)
{
u32 min, max, conversion_pace;
u32 brightness = user_brightness;
@@ -2901,12 +2902,18 @@ static u32 convert_brightness(const struct
amdgpu_dm_backlight_caps *caps,
* 0 to 0x
*/
conversion_pace = 0x101;
- brightness =
- user_brightness
- * conversion_pace
- * (max - min)
- / AMDGPU_MAX_BL_LEVEL
- + min * conversion_pace;
+ if (flag == set_backlight)
+ brightness =
+ user_brightness
+ * conversion_pace
+ * (max - min)
+ / AMDGPU_MAX_BL_LEVEL
+ + min * conversion_pace;
+ else
+ brightness =
+ ((user_brightness - min * conversion_pace)
+* AMDGPU_MAX_BL_LEVEL)
+/ (conversion_pace * (max - min));
} else {
/* TODO
* We are doing a linear interpolation here, which is OK but @@
-2940,24 +2947,35 @@ static int amdgpu_dm_backlight_update_status(struct
backlight_device *bd)
link = (struct dc_link *)dm->backlight_link;
- brightness = convert_brightness(&caps, bd->props.brightness);
+ brightness = convert_brightness(&caps, bd->props.brightness,
+ set_backlight);
// Change brightness based on AUX property
if (caps.aux_support)
return set_backlight_via_aux(link, brightness);
rc = dc_link_set_backlight_level(dm->backlight_link, brightness, 0);
-
return rc ? 0 : 1;
}
static int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd) {
struct amdgpu_display_manager *dm = bl_get_data(bd);
- int ret = dc_link_get_backlight_level(dm->backlight_link);
+ struct amdgpu_dm_backlight_caps caps;
+ int ret;
+
+ amdgpu_dm_update_backlight_caps(dm);
+ caps = dm->backlight_caps;
+
+ ret = dc_link_get_backlight_level(dm->backlight_link);
+ ret = (int)convert_brightness(&caps, (uint32_t)ret, get_backlight);
if (ret == DC_ERROR_UNEXPECTED)
return bd->props.brightness;
- return ret;
+
+ if (ret == AMDGPU_MAX_BL_LEVEL || ret == 0)
+ return ret;
+ else
+ return ret+1;
}
static const struct backlight_ops amdgpu_dm_backlight_ops = { diff --git
a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
index 1df0ce047e1c..d54fc00148f9 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -60,6 +60,11 @@ struct dc;
struct amdgpu_bo;
struct dmub_srv;
+enum convert_backlight {
+ get_backlight,
+ set_backlight
+};
+
struct common_irq_params {
struct amdgpu_device *adev;
enum dc_irq_source irq_src;
--
2.17.1
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Re: [PATCH] mm: Track mmu notifiers in fs_reclaim_acquire/release
On Sun, Jun 21, 2020 at 08:07:08PM +0200, Daniel Vetter wrote:
> On Sun, Jun 21, 2020 at 7:42 PM Qian Cai wrote:
> >
> > On Wed, Jun 10, 2020 at 09:41:01PM +0200, Daniel Vetter wrote:
> > > fs_reclaim_acquire/release nicely catch recursion issues when
> > > allocating GFP_KERNEL memory against shrinkers (which gpu drivers tend
> > > to use to keep the excessive caches in check). For mmu notifier
> > > recursions we do have lockdep annotations since 23b68395c7c7
> > > ("mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end").
> > >
> > > But these only fire if a path actually results in some pte
> > > invalidation - for most small allocations that's very rarely the case.
> > > The other trouble is that pte invalidation can happen any time when
> > > __GFP_RECLAIM is set. Which means only really GFP_ATOMIC is a safe
> > > choice, GFP_NOIO isn't good enough to avoid potential mmu notifier
> > > recursion.
> > >
> > > I was pondering whether we should just do the general annotation, but
> > > there's always the risk for false positives. Plus I'm assuming that
> > > the core fs and io code is a lot better reviewed and tested than
> > > random mmu notifier code in drivers. Hence why I decide to only
> > > annotate for that specific case.
> > >
> > > Furthermore even if we'd create a lockdep map for direct reclaim, we'd
> > > still need to explicit pull in the mmu notifier map - there's a lot
> > > more places that do pte invalidation than just direct reclaim, these
> > > two contexts arent the same.
> > >
> > > Note that the mmu notifiers needing their own independent lockdep map
> > > is also the reason we can't hold them from fs_reclaim_acquire to
> > > fs_reclaim_release - it would nest with the acquistion in the pte
> > > invalidation code, causing a lockdep splat. And we can't remove the
> > > annotations from pte invalidation and all the other places since
> > > they're called from many other places than page reclaim. Hence we can
> > > only do the equivalent of might_lock, but on the raw lockdep map.
> > >
> > > With this we can also remove the lockdep priming added in 66204f1d2d1b
> > > ("mm/mmu_notifiers: prime lockdep") since the new annotations are
> > > strictly more powerful.
> > >
> > > v2: Review from Thomas Hellstrom:
> > > - unbotch the fs_reclaim context check, I accidentally inverted it,
> > > but it didn't blow up because I inverted it immediately
> > > - fix compiling for !CONFIG_MMU_NOTIFIER
> > >
> > > Cc: Thomas Hellström (Intel)
> > > Cc: Andrew Morton
> > > Cc: Jason Gunthorpe
> > > Cc: linux...@kvack.org
> > > Cc: linux-r...@vger.kernel.org
> > > Cc: Maarten Lankhorst
> > > Cc: Christian König
> > > Signed-off-by: Daniel Vetter
> >
> > Replying the right patch here...
> >
> > Reverting this commit [1] fixed the lockdep warning below while applying
> > some memory pressure.
> >
> > [1] linux-next cbf7c9d86d75 ("mm: track mmu notifiers in
> > fs_reclaim_acquire/release")
>
> Hm, then I'm confused because
> - there's not mmut notifier lockdep map in the splat at a..
> - the patch is supposed to not change anything for fs_reclaim (but the
> interim version got that wrong)
> - looking at the paths it's kmalloc vs kswapd, both places I totally
> expect fs_reflaim to be used.
>
> But you're claiming reverting this prevents the lockdep splat. If
> that's right, then my reasoning above is broken somewhere. Someone
> less blind than me having an idea?
>
> Aside this is the first email I've typed, until I realized the first
> report was against the broken patch and that looked like a much more
> reasonable explanation (but didn't quite match up with the code
> paths).
Below diff should undo the functional change in my patch. Can you pls test
whether the lockdep splat is really gone with that? Might need a lot of
testing and memory pressure to be sure, since all these reclaim paths
aren't very deterministic.
-Daniel
---
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d807587c9ae6..27ea763c6155 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4191,11 +4191,6 @@ void fs_reclaim_acquire(gfp_t gfp_mask)
if (gfp_mask & __GFP_FS)
__fs_reclaim_acquire();
-#ifdef CONFIG_MMU_NOTIFIER
- lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
- lock_map_release(&__mmu_notifier_invalidate_range_start_map);
-#endif
-
}
}
EXPORT_SYMBOL_GPL(fs_reclaim_acquire);
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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Re: [PATCH] mm: Track mmu notifiers in fs_reclaim_acquire/release
On Sun, Jun 21, 2020 at 7:42 PM Qian Cai wrote:
>
> On Wed, Jun 10, 2020 at 09:41:01PM +0200, Daniel Vetter wrote:
> > fs_reclaim_acquire/release nicely catch recursion issues when
> > allocating GFP_KERNEL memory against shrinkers (which gpu drivers tend
> > to use to keep the excessive caches in check). For mmu notifier
> > recursions we do have lockdep annotations since 23b68395c7c7
> > ("mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end").
> >
> > But these only fire if a path actually results in some pte
> > invalidation - for most small allocations that's very rarely the case.
> > The other trouble is that pte invalidation can happen any time when
> > __GFP_RECLAIM is set. Which means only really GFP_ATOMIC is a safe
> > choice, GFP_NOIO isn't good enough to avoid potential mmu notifier
> > recursion.
> >
> > I was pondering whether we should just do the general annotation, but
> > there's always the risk for false positives. Plus I'm assuming that
> > the core fs and io code is a lot better reviewed and tested than
> > random mmu notifier code in drivers. Hence why I decide to only
> > annotate for that specific case.
> >
> > Furthermore even if we'd create a lockdep map for direct reclaim, we'd
> > still need to explicit pull in the mmu notifier map - there's a lot
> > more places that do pte invalidation than just direct reclaim, these
> > two contexts arent the same.
> >
> > Note that the mmu notifiers needing their own independent lockdep map
> > is also the reason we can't hold them from fs_reclaim_acquire to
> > fs_reclaim_release - it would nest with the acquistion in the pte
> > invalidation code, causing a lockdep splat. And we can't remove the
> > annotations from pte invalidation and all the other places since
> > they're called from many other places than page reclaim. Hence we can
> > only do the equivalent of might_lock, but on the raw lockdep map.
> >
> > With this we can also remove the lockdep priming added in 66204f1d2d1b
> > ("mm/mmu_notifiers: prime lockdep") since the new annotations are
> > strictly more powerful.
> >
> > v2: Review from Thomas Hellstrom:
> > - unbotch the fs_reclaim context check, I accidentally inverted it,
> > but it didn't blow up because I inverted it immediately
> > - fix compiling for !CONFIG_MMU_NOTIFIER
> >
> > Cc: Thomas Hellström (Intel)
> > Cc: Andrew Morton
> > Cc: Jason Gunthorpe
> > Cc: linux...@kvack.org
> > Cc: linux-r...@vger.kernel.org
> > Cc: Maarten Lankhorst
> > Cc: Christian König
> > Signed-off-by: Daniel Vetter
>
> Replying the right patch here...
>
> Reverting this commit [1] fixed the lockdep warning below while applying
> some memory pressure.
>
> [1] linux-next cbf7c9d86d75 ("mm: track mmu notifiers in
> fs_reclaim_acquire/release")
Hm, then I'm confused because
- there's not mmut notifier lockdep map in the splat at a..
- the patch is supposed to not change anything for fs_reclaim (but the
interim version got that wrong)
- looking at the paths it's kmalloc vs kswapd, both places I totally
expect fs_reflaim to be used.
But you're claiming reverting this prevents the lockdep splat. If
that's right, then my reasoning above is broken somewhere. Someone
less blind than me having an idea?
Aside this is the first email I've typed, until I realized the first
report was against the broken patch and that looked like a much more
reasonable explanation (but didn't quite match up with the code
paths).
Thanks, Daniel
>
> [ 190.455003][ T369] WARNING: possible circular locking dependency detected
> [ 190.487291][ T369] 5.8.0-rc1-next-20200621 #1 Not tainted
> [ 190.512363][ T369] --
> [ 190.543354][ T369] kswapd3/369 is trying to acquire lock:
> [ 190.568523][ T369] 889fcf694528
> (&xfs_nondir_ilock_class){}-{3:3}, at: xfs_reclaim_inode+0xdf/0x860
> spin_lock at include/linux/spinlock.h:353
> (inlined by) xfs_iflags_test_and_set at fs/xfs/xfs_inode.h:166
> (inlined by) xfs_iflock_nowait at fs/xfs/xfs_inode.h:249
> (inlined by) xfs_reclaim_inode at fs/xfs/xfs_icache.c:1127
> [ 190.614359][ T369]
> [ 190.614359][ T369] but task is already holding lock:
> [ 190.647763][ T369] b50ced00 (fs_reclaim){+.+.}-{0:0}, at:
> __fs_reclaim_acquire+0x0/0x30
> __fs_reclaim_acquire at mm/page_alloc.c:4200
> [ 190.687845][ T369]
> [ 190.687845][ T369] which lock already depends on the new lock.
> [ 190.687845][ T369]
> [ 190.73
Re: [PATCH 01/18] mm: Track mmu notifiers in fs_reclaim_acquire/release
On Sun, Jun 21, 2020 at 7:01 PM Qian Cai wrote:
>
> On Thu, Jun 04, 2020 at 10:12:07AM +0200, Daniel Vetter wrote:
> > fs_reclaim_acquire/release nicely catch recursion issues when
> > allocating GFP_KERNEL memory against shrinkers (which gpu drivers tend
> > to use to keep the excessive caches in check). For mmu notifier
> > recursions we do have lockdep annotations since 23b68395c7c7
> > ("mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end").
> >
> > But these only fire if a path actually results in some pte
> > invalidation - for most small allocations that's very rarely the case.
> > The other trouble is that pte invalidation can happen any time when
> > __GFP_RECLAIM is set. Which means only really GFP_ATOMIC is a safe
> > choice, GFP_NOIO isn't good enough to avoid potential mmu notifier
> > recursion.
> >
> > I was pondering whether we should just do the general annotation, but
> > there's always the risk for false positives. Plus I'm assuming that
> > the core fs and io code is a lot better reviewed and tested than
> > random mmu notifier code in drivers. Hence why I decide to only
> > annotate for that specific case.
> >
> > Furthermore even if we'd create a lockdep map for direct reclaim, we'd
> > still need to explicit pull in the mmu notifier map - there's a lot
> > more places that do pte invalidation than just direct reclaim, these
> > two contexts arent the same.
> >
> > Note that the mmu notifiers needing their own independent lockdep map
> > is also the reason we can't hold them from fs_reclaim_acquire to
> > fs_reclaim_release - it would nest with the acquistion in the pte
> > invalidation code, causing a lockdep splat. And we can't remove the
> > annotations from pte invalidation and all the other places since
> > they're called from many other places than page reclaim. Hence we can
> > only do the equivalent of might_lock, but on the raw lockdep map.
> >
> > With this we can also remove the lockdep priming added in 66204f1d2d1b
> > ("mm/mmu_notifiers: prime lockdep") since the new annotations are
> > strictly more powerful.
> >
> > Cc: Andrew Morton
> > Cc: Jason Gunthorpe
> > Cc: linux...@kvack.org
> > Cc: linux-r...@vger.kernel.org
> > Cc: Maarten Lankhorst
> > Cc: Christian König
> > Signed-off-by: Daniel Vetter
>
> Reverting this commit fixed the lockdep splat below while applying some
> memory pressure,
This is a broken version of the patch, please use the one Andrew
merged into -mm.
Thanks, Daniel
>
> [ 190.455003][ T369] WARNING: possible circular locking dependency detected
> [ 190.487291][ T369] 5.8.0-rc1-next-20200621 #1 Not tainted
> [ 190.512363][ T369] --
> [ 190.543354][ T369] kswapd3/369 is trying to acquire lock:
> [ 190.568523][ T369] 889fcf694528
> (&xfs_nondir_ilock_class){}-{3:3}, at: xfs_reclaim_inode+0xdf/0x860
> spin_lock at include/linux/spinlock.h:353
> (inlined by) xfs_iflags_test_and_set at fs/xfs/xfs_inode.h:166
> (inlined by) xfs_iflock_nowait at fs/xfs/xfs_inode.h:249
> (inlined by) xfs_reclaim_inode at fs/xfs/xfs_icache.c:1127
> [ 190.614359][ T369]
> [ 190.614359][ T369] but task is already holding lock:
> [ 190.647763][ T369] b50ced00 (fs_reclaim){+.+.}-{0:0}, at:
> __fs_reclaim_acquire+0x0/0x30
> __fs_reclaim_acquire at mm/page_alloc.c:4200
> [ 190.687845][ T369]
> [ 190.687845][ T369] which lock already depends on the new lock.
> [ 190.687845][ T369]
> [ 190.734890][ T369]
> [ 190.734890][ T369] the existing dependency chain (in reverse order) is:
> [ 190.775991][ T369]
> [ 190.775991][ T369] -> #1 (fs_reclaim){+.+.}-{0:0}:
> [ 190.808150][ T369]fs_reclaim_acquire+0x77/0x80
> [ 190.832152][ T369]slab_pre_alloc_hook.constprop.52+0x20/0x120
> slab_pre_alloc_hook at mm/slab.h:507
> [ 190.862173][ T369]kmem_cache_alloc+0x43/0x2a0
> [ 190.885602][ T369]kmem_zone_alloc+0x113/0x3ef
> kmem_zone_alloc at fs/xfs/kmem.c:129
> [ 190.908702][ T369]xfs_inode_item_init+0x1d/0xa0
> xfs_inode_item_init at fs/xfs/xfs_inode_item.c:639
> [ 190.934461][ T369]xfs_trans_ijoin+0x96/0x100
> xfs_trans_ijoin at fs/xfs/libxfs/xfs_trans_inode.c:34
> [ 190.961530][ T369]xfs_setattr_nonsize+0x1a6/0xcd0
> xfs_setattr_nonsize at fs/xfs/xfs_iops.c:716
> [ 190.987331][ T369]xfs_vn_setattr+0x133/0x160
> xfs_vn_setattr at fs/xfs/xfs_iops.c:1081
> [ 191.010476][ T369]notify_change+0x6c5/0xba1
> notify_change at fs
