Panfrost DRM driver uses devfreq to perform DVFS, while using simple_ondemand
devfreq governor by default. This causes driver initialization to fail on
boot when simple_ondemand governor isn't built into the kernel statically,
as a result of the missing module dependency and, consequently, the required
governor module not being included in the initial ramdisk. Thus, let's mark
simple_ondemand governor as a softdep for Panfrost, to have its kernel module
included in the initial ramdisk.
This is a rather longstanding issue that has forced distributions to build
devfreq governors statically into their kernels, [1][2] or has forced users
to introduce some unnecessary workarounds. [3]
For future reference, not having support for the simple_ondemand governor in
the initial ramdisk produces errors in the kernel log similar to these below,
which were taken from a Pine64 RockPro64:
panfrost ff9a0000.gpu: [drm:panfrost_devfreq_init [panfrost]] *ERROR* Couldn't initialize GPU devfreq
panfrost ff9a0000.gpu: Fatal error during GPU init
panfrost: probe of ff9a0000.gpu failed with error -22
Having simple_ondemand marked as a softdep for Panfrost may not resolve this
issue for all Linux distributions. In particular, it will remain unresolved
for the distributions whose utilities for the initial ramdisk generation do
not handle the available softdep information [4] properly yet. However, some
Linux distributions already handle softdeps properly while generating their
initial ramdisks, [5] and this is a prerequisite step in the right direction
for the distributions that don't handle them properly yet.
[1] https://gitlab.manjaro.org/manjaro-arm/packages/core/linux/-/blob/linux61/c…
[2] https://salsa.debian.org/kernel-team/linux/-/merge_requests/1066
[3] https://forum.pine64.org/showthread.php?tid=15458
[4] https://git.kernel.org/pub/scm/utils/kernel/kmod/kmod.git/commit/?id=49d8e0…
[5] https://github.com/archlinux/mkinitcpio/commit/97ac4d37aae084a050be512f6d8f…
Cc: Diederik de Haas <didi.debian(a)cknow.org>
Cc: Furkan Kardame <f.kardame(a)manjaro.org>
Cc: stable(a)vger.kernel.org
Fixes: f3ba91228e8e ("drm/panfrost: Add initial panfrost driver")
Signed-off-by: Dragan Simic <dsimic(a)manjaro.org>
---
drivers/gpu/drm/panfrost/panfrost_drv.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index ef9f6c0716d5..149737d7a07e 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -828,3 +828,4 @@ module_platform_driver(panfrost_driver);
MODULE_AUTHOR("Panfrost Project Developers");
MODULE_DESCRIPTION("Panfrost DRM Driver");
MODULE_LICENSE("GPL v2");
+MODULE_SOFTDEP("pre: governor_simpleondemand");
The patch titled
Subject: nilfs2: handle inconsistent state in nilfs_btnode_create_block()
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
nilfs2-handle-inconsistent-state-in-nilfs_btnode_create_block.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Subject: nilfs2: handle inconsistent state in nilfs_btnode_create_block()
Date: Thu, 25 Jul 2024 14:20:07 +0900
Syzbot reported that a buffer state inconsistency was detected in
nilfs_btnode_create_block(), triggering a kernel bug.
It is not appropriate to treat this inconsistency as a bug; it can occur
if the argument block address (the buffer index of the newly created
block) is a virtual block number and has been reallocated due to
corruption of the bitmap used to manage its allocation state.
So, modify nilfs_btnode_create_block() and its callers to treat it as a
possible filesystem error, rather than triggering a kernel bug.
Link: https://lkml.kernel.org/r/20240725052007.4562-1-konishi.ryusuke@gmail.com
Fixes: a60be987d45d ("nilfs2: B-tree node cache")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Reported-by: syzbot+89cc4f2324ed37988b60(a)syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=89cc4f2324ed37988b60
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
fs/nilfs2/btnode.c | 25 ++++++++++++++++++++-----
fs/nilfs2/btree.c | 4 ++--
2 files changed, 22 insertions(+), 7 deletions(-)
--- a/fs/nilfs2/btnode.c~nilfs2-handle-inconsistent-state-in-nilfs_btnode_create_block
+++ a/fs/nilfs2/btnode.c
@@ -51,12 +51,21 @@ nilfs_btnode_create_block(struct address
bh = nilfs_grab_buffer(inode, btnc, blocknr, BIT(BH_NILFS_Node));
if (unlikely(!bh))
- return NULL;
+ return ERR_PTR(-ENOMEM);
if (unlikely(buffer_mapped(bh) || buffer_uptodate(bh) ||
buffer_dirty(bh))) {
- brelse(bh);
- BUG();
+ /*
+ * The block buffer at the specified new address was already
+ * in use. This can happen if it is a virtual block number
+ * and has been reallocated due to corruption of the bitmap
+ * used to manage its allocation state (if not, the buffer
+ * clearing of an abandoned b-tree node is missing somewhere).
+ */
+ nilfs_error(inode->i_sb,
+ "state inconsistency probably due to duplicate use of b-tree node block address %llu (ino=%lu)",
+ (unsigned long long)blocknr, inode->i_ino);
+ goto failed;
}
memset(bh->b_data, 0, i_blocksize(inode));
bh->b_bdev = inode->i_sb->s_bdev;
@@ -67,6 +76,12 @@ nilfs_btnode_create_block(struct address
folio_unlock(bh->b_folio);
folio_put(bh->b_folio);
return bh;
+
+failed:
+ folio_unlock(bh->b_folio);
+ folio_put(bh->b_folio);
+ brelse(bh);
+ return ERR_PTR(-EIO);
}
int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr,
@@ -217,8 +232,8 @@ retry:
}
nbh = nilfs_btnode_create_block(btnc, newkey);
- if (!nbh)
- return -ENOMEM;
+ if (IS_ERR(nbh))
+ return PTR_ERR(nbh);
BUG_ON(nbh == obh);
ctxt->newbh = nbh;
--- a/fs/nilfs2/btree.c~nilfs2-handle-inconsistent-state-in-nilfs_btnode_create_block
+++ a/fs/nilfs2/btree.c
@@ -63,8 +63,8 @@ static int nilfs_btree_get_new_block(con
struct buffer_head *bh;
bh = nilfs_btnode_create_block(btnc, ptr);
- if (!bh)
- return -ENOMEM;
+ if (IS_ERR(bh))
+ return PTR_ERR(bh);
set_buffer_nilfs_volatile(bh);
*bhp = bh;
_
Patches currently in -mm which might be from konishi.ryusuke(a)gmail.com are
nilfs2-handle-inconsistent-state-in-nilfs_btnode_create_block.patch