From: Bruce Ashfield <[email protected]>
To partially (or fully) address:
https://bugzilla.yoctoproject.org/show_bug.cgi?id=16217
Integrating the following commit(s) to linux-yocto/6.18:
1/1 [
Author: Ryosuke Yasuoka
Email: [email protected]
Subject: drm/virtio: fix deadlock in display_info_cb by removing hotplug
from dequeue worker
Date: Mon, 13 Jul 2026 22:01:00 +0900
A probe-time deadlock can occur between the dequeue worker and
drm_client_register(). During probe, drm_client_register() holds
clientlist_mutex and calls the fbdev hotplug callback, which triggers an
atomic commit that ends up sleeping in virtio_gpu_queue_ctrl_sgs()
waiting for virtqueue space. The dequeue worker that would free that
space calls virtio_gpu_cmd_get_display_info_cb(), which invokes
drm_kms_helper_hotplug_event() -> drm_client_dev_hotplug(), attempting
to acquire the same clientlist_mutex. Since wake_up() is only called
after the resp_cb loop, the probe thread is never woken and both threads
deadlock.
Fix this by removing the hotplug notification from
virtio_gpu_cmd_get_display_info_cb(). The display data (outputs[i].info)
is still updated synchronously in the callback.
For the init path, drm_client_register() already fires an initial
hotplug when the client is registered, which picks up the connector
state updated by display_info_cb.
For the runtime config_changed path, add a wait_event_timeout() in
config_changed_work_func() so that display_info_cb updates the connector
data before the hotplug notification is sent. Also replace
drm_helper_hpd_irq_event() with drm_kms_helper_hotplug_event() since
virtio-gpu never calls drm_kms_helper_poll_init() and thus
drm_helper_hpd_irq_event() always returns false without doing anything.
Fixes: 27655b9bb9f0 ("drm/client: Send hotplug event after registering a
client")
Closes:
https://syzkaller.appspot.com/bug?id=d6dd6f86d3aaf7eebe7406e45c1c6e549453f224
Closes:
https://syzkaller.appspot.com/bug?id=908bd910da5dd79b88de4cf7baf376cc873a922e
Suggested-by: Dmitry Osipenko <[email protected]>
Signed-off-by: Ryosuke Yasuoka <[email protected]>
Signed-off-by: Dmitry Osipenko <[email protected]>
Link:
https://patch.msgid.link/[email protected]
Signed-off-by: Bruce Ashfield <[email protected]>
]
Signed-off-by: Bruce Ashfield <[email protected]>
---
.../linux/linux-yocto-rt_6.18.bb | 2 +-
.../linux/linux-yocto-tiny_6.18.bb | 2 +-
meta/recipes-kernel/linux/linux-yocto_6.18.bb | 18 +++++++++---------
3 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/meta/recipes-kernel/linux/linux-yocto-rt_6.18.bb
b/meta/recipes-kernel/linux/linux-yocto-rt_6.18.bb
index 6d287cdc7d..9d44c803eb 100644
--- a/meta/recipes-kernel/linux/linux-yocto-rt_6.18.bb
+++ b/meta/recipes-kernel/linux/linux-yocto-rt_6.18.bb
@@ -15,7 +15,7 @@ python () {
raise bb.parse.SkipRecipe("Set PREFERRED_PROVIDER_virtual/kernel to
linux-yocto-rt to enable it")
}
-SRCREV_machine ?= "0156acd2db993abc3baa366fee892d503aab1ccc"
+SRCREV_machine ?= "56572c42354027a50e261f16fe13b057604873e7"
SRCREV_meta ?= "2f71b0a288c307062fc60948ac793d8d51c685e2"
SRC_URI =
"git://git.yoctoproject.org/linux-yocto.git;branch=${KBRANCH};name=machine;protocol=https
\
diff --git a/meta/recipes-kernel/linux/linux-yocto-tiny_6.18.bb
b/meta/recipes-kernel/linux/linux-yocto-tiny_6.18.bb
index 8b9201a73e..7ff47505aa 100644
--- a/meta/recipes-kernel/linux/linux-yocto-tiny_6.18.bb
+++ b/meta/recipes-kernel/linux/linux-yocto-tiny_6.18.bb
@@ -18,7 +18,7 @@ DEPENDS += "openssl-native util-linux-native"
KMETA = "kernel-meta"
KCONF_BSP_AUDIT_LEVEL = "2"
-SRCREV_machine ?= "a05c451ede0dd80b1cc2362b47f36f3c137cbd1e"
+SRCREV_machine ?= "9eb7db1359675f27707b030ba228f381c10cd53e"
SRCREV_meta ?= "2f71b0a288c307062fc60948ac793d8d51c685e2"
PV = "${LINUX_VERSION}+git"
diff --git a/meta/recipes-kernel/linux/linux-yocto_6.18.bb
b/meta/recipes-kernel/linux/linux-yocto_6.18.bb
index 8528869a5e..6111ae89da 100644
--- a/meta/recipes-kernel/linux/linux-yocto_6.18.bb
+++ b/meta/recipes-kernel/linux/linux-yocto_6.18.bb
@@ -17,17 +17,17 @@ KBRANCH:qemux86-64 ?= "v6.18/standard/base"
KBRANCH:qemuloongarch64 ?= "v6.18/standard/base"
KBRANCH:qemumips64 ?= "v6.18/standard/mti-malta"
-SRCREV_machine:qemuarm ?= "162946cfb65f28f0a5f60e927bdae5615e6356a8"
-SRCREV_machine:qemuarm64 ?= "a05c451ede0dd80b1cc2362b47f36f3c137cbd1e"
-SRCREV_machine:qemuloongarch64 ?= "a05c451ede0dd80b1cc2362b47f36f3c137cbd1e"
+SRCREV_machine:qemuarm ?= "78e0248ce3cecd33f63926cd1d54c64e163d076c"
+SRCREV_machine:qemuarm64 ?= "9eb7db1359675f27707b030ba228f381c10cd53e"
+SRCREV_machine:qemuloongarch64 ?= "9eb7db1359675f27707b030ba228f381c10cd53e"
SRCREV_machine:qemumips ?= "62ea92a539f58803a222be98b81118403074206e"
-SRCREV_machine:qemuppc ?= "a05c451ede0dd80b1cc2362b47f36f3c137cbd1e"
-SRCREV_machine:qemuriscv64 ?= "a05c451ede0dd80b1cc2362b47f36f3c137cbd1e"
-SRCREV_machine:qemuriscv32 ?= "a05c451ede0dd80b1cc2362b47f36f3c137cbd1e"
-SRCREV_machine:qemux86 ?= "a05c451ede0dd80b1cc2362b47f36f3c137cbd1e"
-SRCREV_machine:qemux86-64 ?= "a05c451ede0dd80b1cc2362b47f36f3c137cbd1e"
+SRCREV_machine:qemuppc ?= "9eb7db1359675f27707b030ba228f381c10cd53e"
+SRCREV_machine:qemuriscv64 ?= "9eb7db1359675f27707b030ba228f381c10cd53e"
+SRCREV_machine:qemuriscv32 ?= "9eb7db1359675f27707b030ba228f381c10cd53e"
+SRCREV_machine:qemux86 ?= "9eb7db1359675f27707b030ba228f381c10cd53e"
+SRCREV_machine:qemux86-64 ?= "9eb7db1359675f27707b030ba228f381c10cd53e"
SRCREV_machine:qemumips64 ?= "9fb4ff0187c85426f21fd40d4c61b742800f65c4"
-SRCREV_machine ?= "a05c451ede0dd80b1cc2362b47f36f3c137cbd1e"
+SRCREV_machine ?= "9eb7db1359675f27707b030ba228f381c10cd53e"
SRCREV_meta ?= "2f71b0a288c307062fc60948ac793d8d51c685e2"
# set your preferred provider of linux-yocto to 'linux-yocto-upstream', and
you'll
--
2.43.0
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