<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/include/linux, branch v5.15.172</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v5.15.172</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v5.15.172'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2024-11-14T12:13:40+00:00</updated>
<entry>
<title>fs: create kiocb_{start,end}_write() helpers</title>
<updated>2024-11-14T12:13:40+00:00</updated>
<author>
<name>Amir Goldstein</name>
<email>amir73il@gmail.com</email>
</author>
<published>2023-08-17T14:13:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=9386396a43ef193b2a88f044b862801fcaff0234'/>
<id>urn:sha1:9386396a43ef193b2a88f044b862801fcaff0234</id>
<content type='text'>
Commit ed0360bbab72b829437b67ebb2f9cfac19f59dfe upstream.

aio, io_uring, cachefiles and overlayfs, all open code an ugly variant
of file_{start,end}_write() to silence lockdep warnings.

Create helpers for this lockdep dance so we can use the helpers in all
the callers.

Suggested-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Reviewed-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Message-Id: &lt;20230817141337.1025891-4-amir73il@gmail.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>posix-cpu-timers: Clear TICK_DEP_BIT_POSIX_TIMER on clone</title>
<updated>2024-11-14T12:13:39+00:00</updated>
<author>
<name>Benjamin Segall</name>
<email>bsegall@google.com</email>
</author>
<published>2024-10-26T01:35:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=e70ec8ab9fd3352d619320acef03157d88d32c46'/>
<id>urn:sha1:e70ec8ab9fd3352d619320acef03157d88d32c46</id>
<content type='text'>
[ Upstream commit b5413156bad91dc2995a5c4eab1b05e56914638a ]

When cloning a new thread, its posix_cputimers are not inherited, and
are cleared by posix_cputimers_init(). However, this does not clear the
tick dependency it creates in tsk-&gt;tick_dep_mask, and the handler does
not reach the code to clear the dependency if there were no timers to
begin with.

Thus if a thread has a cputimer running before clone/fork, all
descendants will prevent nohz_full unless they create a cputimer of
their own.

Fix this by entirely clearing the tick_dep_mask in copy_process().
(There is currently no inherited state that needs a tick dependency)

Process-wide timers do not have this problem because fork does not copy
signal_struct as a baseline, it creates one from scratch.

Fixes: b78783000d5c ("posix-cpu-timers: Migrate to use new tick dependency mask model")
Signed-off-by: Ben Segall &lt;bsegall@google.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Frederic Weisbecker &lt;frederic@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/xm26o737bq8o.fsf@google.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>NFSv3: handle out-of-order write replies.</title>
<updated>2024-11-14T12:13:36+00:00</updated>
<author>
<name>NeilBrown</name>
<email>neilb@suse.de</email>
</author>
<published>2023-03-21T22:27:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=dbfdfb2eb7f20657704e399cf88008f0cd68fc02'/>
<id>urn:sha1:dbfdfb2eb7f20657704e399cf88008f0cd68fc02</id>
<content type='text'>
[ Upstream commit 3db63daabe210af32a09533fe7d8d47c711a103c ]

NFSv3 includes pre/post wcc attributes which allow the client to
determine if all changes to the file have been made by the client
itself, or if any might have been made by some other client.

If there are gaps in the pre/post ctime sequence it must be assumed that
some other client changed the file in that gap and the local cache must
be suspect.  The next time the file is opened the cache should be
invalidated.

Since Commit 1c341b777501 ("NFS: Add deferred cache invalidation for
close-to-open consistency violations") in linux 5.3 the Linux client has
been triggering this invalidation.  The chunk in nfs_update_inode() in
particularly triggers.

Unfortunately Linux NFS assumes that all replies will be processed in
the order sent, and will arrive in the order processed.  This is not
true in general.  Consequently Linux NFS might ignore the wcc info in a
WRITE reply because the reply is in response to a WRITE that was sent
before some other request for which a reply has already been seen.  This
is detected by Linux using the gencount tests in nfs_inode_attr_cmp().

Also, when the gencount tests pass it is still possible that the request
were processed on the server in a different order, and a gap seen in
the ctime sequence might be filled in by a subsequent reply, so gaps
should not immediately trigger delayed invalidation.

The net result is that writing to a server and then reading the file
back can result in going to the server for the read rather than serving
it from cache - all because a couple of replies arrived out-of-order.
This is a performance regression over kernels before 5.3, though the
change in 5.3 is a correctness improvement.

This has been seen with Linux writing to a Netapp server which
occasionally re-orders requests.  In testing the majority of requests
were in-order, but a few (maybe 2 or three at a time) could be
re-ordered.

This patch addresses the problem by recording any gaps seen in the
pre/post ctime sequence and not triggering invalidation until either
there are too many gaps to fit in the table, or until there are no more
active writes and the remaining gaps cannot be resolved.

We allocate a table of 16 gaps on demand.  If the allocation fails we
revert to current behaviour which is of little cost as we are unlikely
to be able to cache the writes anyway.

In the table we store "start-&gt;end" pair when iversion is updated and
"end&lt;-start" pairs pre/post pairs reported by the server.  Usually these
exactly cancel out and so nothing is stored.  When there are
out-of-order replies we do store gaps and these will eventually be
cancelled against later replies when this client is the only writer.

If the final write is out-of-order there may be one gap remaining when
the file is closed.  This will be noticed and if there is precisely on
gap and if the iversion can be advanced to match it, then we do so.

This patch makes no attempt to handle directories correctly.  The same
problem potentially exists in the out-of-order replies to create/unlink
requests can cause future lookup requires to be sent to the server
unnecessarily.  A similar scheme using the same primitives could be used
to notice and handle out-of-order replies.

Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Anna Schumaker &lt;Anna.Schumaker@Netapp.com&gt;
Stable-dep-of: 867da60d463b ("nfs: avoid i_lock contention in nfs_clear_invalid_mapping")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>usb: gadget: Add function wakeup support</title>
<updated>2024-11-01T00:52:35+00:00</updated>
<author>
<name>Elson Roy Serrao</name>
<email>quic_eserrao@quicinc.com</email>
</author>
<published>2023-03-24T21:47:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c3f3926854b12adfd1ca4a20381c108c15733996'/>
<id>urn:sha1:c3f3926854b12adfd1ca4a20381c108c15733996</id>
<content type='text'>
[ Upstream commit f0db885fb05d35befa81896db6b19eb3ee9ccdfe ]

USB3.2 spec section 9.2.5.4 quotes that a function may signal that
it wants to exit from Function Suspend by sending a Function
Wake Notification to the host if it is enabled for function
remote wakeup. Add an api in composite layer that can be used
by the function drivers to support this feature. Also expose
a gadget op so that composite layer can trigger a wakeup request
to the UDC driver.

Reviewed-by: Thinh Nguyen &lt;Thinh.Nguyen@synopsys.com&gt;
Signed-off-by: Elson Roy Serrao &lt;quic_eserrao@quicinc.com&gt;
Link: https://lore.kernel.org/r/1679694482-16430-4-git-send-email-quic_eserrao@quicinc.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Stable-dep-of: 705e3ce37bcc ("usb: dwc3: core: Fix system suspend on TI AM62 platforms")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>irqchip/gic-v4: Don't allow a VMOVP on a dying VPE</title>
<updated>2024-10-22T13:40:46+00:00</updated>
<author>
<name>Marc Zyngier</name>
<email>maz@kernel.org</email>
</author>
<published>2024-10-02T20:49:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=755b9532c885b8761fb135fedcd705e21e61cccb'/>
<id>urn:sha1:755b9532c885b8761fb135fedcd705e21e61cccb</id>
<content type='text'>
commit 1442ee0011983f0c5c4b92380e6853afb513841a upstream.

Kunkun Jiang reported that there is a small window of opportunity for
userspace to force a change of affinity for a VPE while the VPE has already
been unmapped, but the corresponding doorbell interrupt still visible in
/proc/irq/.

Plug the race by checking the value of vmapp_count, which tracks whether
the VPE is mapped ot not, and returning an error in this case.

This involves making vmapp_count common to both GICv4.1 and its v4.0
ancestor.

Fixes: 64edfaa9a234 ("irqchip/gic-v4.1: Implement the v4.1 flavour of VMAPP")
Reported-by: Kunkun Jiang &lt;jiangkunkun@huawei.com&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/c182ece6-2ba0-ce4f-3404-dba7a3ab6c52@huawei.com
Link: https://lore.kernel.org/all/20241002204959.2051709-1-maz@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>net: enetc: add missing static descriptor and inline keyword</title>
<updated>2024-10-22T13:40:40+00:00</updated>
<author>
<name>Wei Fang</name>
<email>wei.fang@nxp.com</email>
</author>
<published>2024-10-11T03:01:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=dcc7207483b22437b26ce7e99e6613b2322757c7'/>
<id>urn:sha1:dcc7207483b22437b26ce7e99e6613b2322757c7</id>
<content type='text'>
commit 1d7b2ce43d2c22a21dadaf689cb36a69570346a6 upstream.

Fix the build warnings when CONFIG_FSL_ENETC_MDIO is not enabled.
The detailed warnings are shown as follows.

include/linux/fsl/enetc_mdio.h:62:18: warning: no previous prototype for function 'enetc_hw_alloc' [-Wmissing-prototypes]
      62 | struct enetc_hw *enetc_hw_alloc(struct device *dev, void __iomem *port_regs)
         |                  ^
include/linux/fsl/enetc_mdio.h:62:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
      62 | struct enetc_hw *enetc_hw_alloc(struct device *dev, void __iomem *port_regs)
         | ^
         | static
8 warnings generated.

Fixes: 6517798dd343 ("enetc: Make MDIO accessors more generic and export to include/linux/fsl")
Cc: stable@vger.kernel.org
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/oe-kbuild-all/202410102136.jQHZOcS4-lkp@intel.com/
Signed-off-by: Wei Fang &lt;wei.fang@nxp.com&gt;
Reviewed-by: Claudiu Manoil &lt;claudiu.manoil@nxp.com&gt;
Reviewed-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Link: https://patch.msgid.link/20241011030103.392362-1-wei.fang@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>NFSv4: Prevent NULL-pointer dereference in nfs42_complete_copies()</title>
<updated>2024-10-17T13:11:53+00:00</updated>
<author>
<name>Yanjun Zhang</name>
<email>zhangyanjun@cestc.cn</email>
</author>
<published>2024-10-01T08:39:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=584c019baedddec3fd634053e8fb2d8836108d38'/>
<id>urn:sha1:584c019baedddec3fd634053e8fb2d8836108d38</id>
<content type='text'>
[ Upstream commit a848c29e3486189aaabd5663bc11aea50c5bd144 ]

On the node of an NFS client, some files saved in the mountpoint of the
NFS server were copied to another location of the same NFS server.
Accidentally, the nfs42_complete_copies() got a NULL-pointer dereference
crash with the following syslog:

[232064.838881] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232064.839360] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232066.588183] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058
[232066.588586] Mem abort info:
[232066.588701]   ESR = 0x0000000096000007
[232066.588862]   EC = 0x25: DABT (current EL), IL = 32 bits
[232066.589084]   SET = 0, FnV = 0
[232066.589216]   EA = 0, S1PTW = 0
[232066.589340]   FSC = 0x07: level 3 translation fault
[232066.589559] Data abort info:
[232066.589683]   ISV = 0, ISS = 0x00000007
[232066.589842]   CM = 0, WnR = 0
[232066.589967] user pgtable: 64k pages, 48-bit VAs, pgdp=00002000956ff400
[232066.590231] [0000000000000058] pgd=08001100ae100003, p4d=08001100ae100003, pud=08001100ae100003, pmd=08001100b3c00003, pte=0000000000000000
[232066.590757] Internal error: Oops: 96000007 [#1] SMP
[232066.590958] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm vhost_net vhost vhost_iotlb tap tun ipt_rpfilter xt_multiport ip_set_hash_ip ip_set_hash_net xfrm_interface xfrm6_tunnel tunnel4 tunnel6 esp4 ah4 wireguard libcurve25519_generic veth xt_addrtype xt_set nf_conntrack_netlink ip_set_hash_ipportnet ip_set_hash_ipportip ip_set_bitmap_port ip_set_hash_ipport dummy ip_set ip_vs_sh ip_vs_wrr ip_vs_rr ip_vs iptable_filter sch_ingress nfnetlink_cttimeout vport_gre ip_gre ip_tunnel gre vport_geneve geneve vport_vxlan vxlan ip6_udp_tunnel udp_tunnel openvswitch nf_conncount dm_round_robin dm_service_time dm_multipath xt_nat xt_MASQUERADE nft_chain_nat nf_nat xt_mark xt_conntrack xt_comment nft_compat nft_counter nf_tables nfnetlink ocfs2 ocfs2_nodemanager ocfs2_stackglue iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ipmi_ssif nbd overlay 8021q garp mrp bonding tls rfkill sunrpc ext4 mbcache jbd2
[232066.591052]  vfat fat cas_cache cas_disk ses enclosure scsi_transport_sas sg acpi_ipmi ipmi_si ipmi_devintf ipmi_msghandler ip_tables vfio_pci vfio_pci_core vfio_virqfd vfio_iommu_type1 vfio dm_mirror dm_region_hash dm_log dm_mod nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc fuse xfs libcrc32c ast drm_vram_helper qla2xxx drm_kms_helper syscopyarea crct10dif_ce sysfillrect ghash_ce sysimgblt sha2_ce fb_sys_fops cec sha256_arm64 sha1_ce drm_ttm_helper ttm nvme_fc igb sbsa_gwdt nvme_fabrics drm nvme_core i2c_algo_bit i40e scsi_transport_fc megaraid_sas aes_neon_bs
[232066.596953] CPU: 6 PID: 4124696 Comm: 10.253.166.125- Kdump: loaded Not tainted 5.15.131-9.cl9_ocfs2.aarch64 #1
[232066.597356] Hardware name: Great Wall .\x93\x8e...RF6260 V5/GWMSSE2GL1T, BIOS T656FBE_V3.0.18 2024-01-06
[232066.597721] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[232066.598034] pc : nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.598327] lr : nfs4_reclaim_open_state+0x12c/0x800 [nfsv4]
[232066.598595] sp : ffff8000f568fc70
[232066.598731] x29: ffff8000f568fc70 x28: 0000000000001000 x27: ffff21003db33000
[232066.599030] x26: ffff800005521ae0 x25: ffff0100f98fa3f0 x24: 0000000000000001
[232066.599319] x23: ffff800009920008 x22: ffff21003db33040 x21: ffff21003db33050
[232066.599628] x20: ffff410172fe9e40 x19: ffff410172fe9e00 x18: 0000000000000000
[232066.599914] x17: 0000000000000000 x16: 0000000000000004 x15: 0000000000000000
[232066.600195] x14: 0000000000000000 x13: ffff800008e685a8 x12: 00000000eac0c6e6
[232066.600498] x11: 0000000000000000 x10: 0000000000000008 x9 : ffff8000054e5828
[232066.600784] x8 : 00000000ffffffbf x7 : 0000000000000001 x6 : 000000000a9eb14a
[232066.601062] x5 : 0000000000000000 x4 : ffff70ff8a14a800 x3 : 0000000000000058
[232066.601348] x2 : 0000000000000001 x1 : 54dce46366daa6c6 x0 : 0000000000000000
[232066.601636] Call trace:
[232066.601749]  nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.601998]  nfs4_do_reclaim+0x1b8/0x28c [nfsv4]
[232066.602218]  nfs4_state_manager+0x928/0x10f0 [nfsv4]
[232066.602455]  nfs4_run_state_manager+0x78/0x1b0 [nfsv4]
[232066.602690]  kthread+0x110/0x114
[232066.602830]  ret_from_fork+0x10/0x20
[232066.602985] Code: 1400000d f9403f20 f9402e61 91016003 (f9402c00)
[232066.603284] SMP: stopping secondary CPUs
[232066.606936] Starting crashdump kernel...
[232066.607146] Bye!

Analysing the vmcore, we know that nfs4_copy_state listed by destination
nfs_server-&gt;ss_copies was added by the field copies in handle_async_copy(),
and we found a waiting copy process with the stack as:
PID: 3511963  TASK: ffff710028b47e00  CPU: 0   COMMAND: "cp"
 #0 [ffff8001116ef740] __switch_to at ffff8000081b92f4
 #1 [ffff8001116ef760] __schedule at ffff800008dd0650
 #2 [ffff8001116ef7c0] schedule at ffff800008dd0a00
 #3 [ffff8001116ef7e0] schedule_timeout at ffff800008dd6aa0
 #4 [ffff8001116ef860] __wait_for_common at ffff800008dd166c
 #5 [ffff8001116ef8e0] wait_for_completion_interruptible at ffff800008dd1898
 #6 [ffff8001116ef8f0] handle_async_copy at ffff8000055142f4 [nfsv4]
 #7 [ffff8001116ef970] _nfs42_proc_copy at ffff8000055147c8 [nfsv4]
 #8 [ffff8001116efa80] nfs42_proc_copy at ffff800005514cf0 [nfsv4]
 #9 [ffff8001116efc50] __nfs4_copy_file_range.constprop.0 at ffff8000054ed694 [nfsv4]

The NULL-pointer dereference was due to nfs42_complete_copies() listed
the nfs_server-&gt;ss_copies by the field ss_copies of nfs4_copy_state.
So the nfs4_copy_state address ffff0100f98fa3f0 was offset by 0x10 and
the data accessed through this pointer was also incorrect. Generally,
the ordered list nfs4_state_owner-&gt;so_states indicate open(O_RDWR) or
open(O_WRITE) states are reclaimed firstly by nfs4_reclaim_open_state().
When destination state reclaim is failed with NFS_STATE_RECOVERY_FAILED
and copies are not deleted in nfs_server-&gt;ss_copies, the source state
may be passed to the nfs42_complete_copies() process earlier, resulting
in this crash scene finally. To solve this issue, we add a list_head
nfs_server-&gt;ss_src_copies for a server-to-server copy specially.

Fixes: 0e65a32c8a56 ("NFS: handle source server reboot")
Signed-off-by: Yanjun Zhang &lt;zhangyanjun@cestc.cn&gt;
Reviewed-by: Trond Myklebust &lt;trond.myklebust@hammerspace.com&gt;
Signed-off-by: Anna Schumaker &lt;anna.schumaker@oracle.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>PCI: Add function 0 DMA alias quirk for Glenfly Arise chip</title>
<updated>2024-10-17T13:11:50+00:00</updated>
<author>
<name>WangYuli</name>
<email>wangyuli@uniontech.com</email>
</author>
<published>2024-08-23T09:57:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=eb54979471aa97182e05aa4e91a1072fa862bf62'/>
<id>urn:sha1:eb54979471aa97182e05aa4e91a1072fa862bf62</id>
<content type='text'>
[ Upstream commit 9246b487ab3c3b5993aae7552b7a4c541cc14a49 ]

Add DMA support for audio function of Glenfly Arise chip, which uses
Requester ID of function 0.

Link: https://lore.kernel.org/r/CA2BBD087345B6D1+20240823095708.3237375-1-wangyuli@uniontech.com
Signed-off-by: SiyuLi &lt;siyuli@glenfly.com&gt;
Signed-off-by: WangYuli &lt;wangyuli@uniontech.com&gt;
[bhelgaas: lower-case hex to match local code, drop unused Device IDs]
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>i2c: core: Lock address during client device instantiation</title>
<updated>2024-10-17T13:11:43+00:00</updated>
<author>
<name>Heiner Kallweit</name>
<email>hkallweit1@gmail.com</email>
</author>
<published>2024-08-15T19:44:50+00:00</published>
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[ Upstream commit 8d3cefaf659265aa82b0373a563fdb9d16a2b947 ]

Krzysztof reported an issue [0] which is caused by parallel attempts to
instantiate the same I2C client device. This can happen if driver
supports auto-detection, but certain devices are also instantiated
explicitly.
The original change isn't actually wrong, it just revealed that I2C core
isn't prepared yet to handle this scenario.
Calls to i2c_new_client_device() can be nested, therefore we can't use a
simple mutex here. Parallel instantiation of devices at different addresses
is ok, so we just have to prevent parallel instantiation at the same address.
We can use a bitmap with one bit per 7-bit I2C client address, and atomic
bit operations to set/check/clear bits.
Now a parallel attempt to instantiate a device at the same address will
result in -EBUSY being returned, avoiding the "sysfs: cannot create duplicate
filename" splash.

Note: This patch version includes small cosmetic changes to the Tested-by
      version, only functional change is that address locking is supported
      for slave addresses too.

[0] https://lore.kernel.org/linux-i2c/9479fe4e-eb0c-407e-84c0-bd60c15baf74@ans.pl/T/#m12706546e8e2414d8f1a0dc61c53393f731685cc

Fixes: caba40ec3531 ("eeprom: at24: Probe for DDR3 thermal sensor in the SPD case")
Cc: stable@vger.kernel.org
Tested-by: Krzysztof Piotr Oledzki &lt;ole@ans.pl&gt;
Signed-off-by: Heiner Kallweit &lt;hkallweit1@gmail.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa+renesas@sang-engineering.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>i2c: create debugfs entry per adapter</title>
<updated>2024-10-17T13:11:43+00:00</updated>
<author>
<name>Wolfram Sang</name>
<email>wsa+renesas@sang-engineering.com</email>
</author>
<published>2023-11-12T22:54:41+00:00</published>
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[ Upstream commit 73febd775bdbdb98c81255ff85773ac410ded5c4 ]

Two drivers already implement custom debugfs handling for their
i2c_adapter and more will come. So, let the core create a debugfs
directory per adapter and pass that to drivers for their debugfs files.

Signed-off-by: Wolfram Sang &lt;wsa+renesas@sang-engineering.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa@kernel.org&gt;
Stable-dep-of: 8d3cefaf6592 ("i2c: core: Lock address during client device instantiation")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
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