<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/rpmsg, branch v6.0-rc1</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>rpmsg: convert sysfs snprintf to sysfs_emit</title>
<updated>2022-07-17T04:08:47+00:00</updated>
<author>
<name>Xuezhi Zhang</name>
<email>zhangxuezhi1@coolpad.com</email>
</author>
<published>2022-06-07T12:06:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7113ac825371c17c15e2d0be79d850e5e16d3328'/>
<id>7113ac825371c17c15e2d0be79d850e5e16d3328</id>
<content type='text'>
Fix the following coccicheck warning:
drivers/rpmsg/qcom_glink_native.c:1677:8-16:
WARNING: use scnprintf or sprintf

Signed-off-by: Xuezhi Zhang &lt;zhangxuezhi1@coolpad.com&gt;
Signed-off-by: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Link: https://lore.kernel.org/r/20220607120649.78436-1-zhangxuezhi1@coolpad.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fix the following coccicheck warning:
drivers/rpmsg/qcom_glink_native.c:1677:8-16:
WARNING: use scnprintf or sprintf

Signed-off-by: Xuezhi Zhang &lt;zhangxuezhi1@coolpad.com&gt;
Signed-off-by: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Link: https://lore.kernel.org/r/20220607120649.78436-1-zhangxuezhi1@coolpad.com
</pre>
</div>
</content>
</entry>
<entry>
<title>rpmsg: qcom_smd: Fix refcount leak in qcom_smd_parse_edge</title>
<updated>2022-07-17T03:15:40+00:00</updated>
<author>
<name>Miaoqian Lin</name>
<email>linmq006@gmail.com</email>
</author>
<published>2022-05-11T12:07:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=65382585f067d4256ba087934f30f85c9b6984de'/>
<id>65382585f067d4256ba087934f30f85c9b6984de</id>
<content type='text'>
of_parse_phandle() returns a node pointer with refcount
incremented, we should use of_node_put() on it when done.

Fixes: 53e2822e56c7 ("rpmsg: Introduce Qualcomm SMD backend")
Signed-off-by: Miaoqian Lin &lt;linmq006@gmail.com&gt;
Signed-off-by: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Link: https://lore.kernel.org/r/20220511120737.57374-1-linmq006@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
of_parse_phandle() returns a node pointer with refcount
incremented, we should use of_node_put() on it when done.

Fixes: 53e2822e56c7 ("rpmsg: Introduce Qualcomm SMD backend")
Signed-off-by: Miaoqian Lin &lt;linmq006@gmail.com&gt;
Signed-off-by: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Link: https://lore.kernel.org/r/20220511120737.57374-1-linmq006@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>rpmsg: qcom: correct kerneldoc</title>
<updated>2022-07-17T03:13:32+00:00</updated>
<author>
<name>Krzysztof Kozlowski</name>
<email>krzysztof.kozlowski@linaro.org</email>
</author>
<published>2022-05-19T07:33:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=101042f4c0eb2daa331b4f7ce32c6d547114830a'/>
<id>101042f4c0eb2daa331b4f7ce32c6d547114830a</id>
<content type='text'>
Correct kerneldoc warnings like:

  drivers/rpmsg/qcom_glink_ssr.c:45:
    warning: expecting prototype for G(). Prototype was for GLINK_SSR_DO_CLEANUP() instead

Also fix meaning of 'flag' argument.

Signed-off-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Reviewed-by: Stephen Boyd &lt;sboyd@kernel.org&gt;
Signed-off-by: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Link: https://lore.kernel.org/r/20220519073330.7187-3-krzysztof.kozlowski@linaro.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Correct kerneldoc warnings like:

  drivers/rpmsg/qcom_glink_ssr.c:45:
    warning: expecting prototype for G(). Prototype was for GLINK_SSR_DO_CLEANUP() instead

Also fix meaning of 'flag' argument.

Signed-off-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Reviewed-by: Stephen Boyd &lt;sboyd@kernel.org&gt;
Signed-off-by: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Link: https://lore.kernel.org/r/20220519073330.7187-3-krzysztof.kozlowski@linaro.org
</pre>
</div>
</content>
</entry>
<entry>
<title>rpmsg: qcom: glink: remove unused name</title>
<updated>2022-07-17T03:13:32+00:00</updated>
<author>
<name>Krzysztof Kozlowski</name>
<email>krzysztof.kozlowski@linaro.org</email>
</author>
<published>2022-05-19T07:33:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6c3ebc96ffefbc48297d7c2fd266e9cb78e6941e'/>
<id>6c3ebc96ffefbc48297d7c2fd266e9cb78e6941e</id>
<content type='text'>
The qcom_glink.name is read from DTS but never used further, never
referenced, so drop it.  This also fixes kerneldoc warning:

  drivers/rpmsg/qcom_glink_native.c:125:
    warning: Function parameter or member 'name' not described in 'qcom_glink'

Signed-off-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Reviewed-by: Stephen Boyd &lt;sboyd@kernel.org&gt;
Signed-off-by: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Link: https://lore.kernel.org/r/20220519073330.7187-2-krzysztof.kozlowski@linaro.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The qcom_glink.name is read from DTS but never used further, never
referenced, so drop it.  This also fixes kerneldoc warning:

  drivers/rpmsg/qcom_glink_native.c:125:
    warning: Function parameter or member 'name' not described in 'qcom_glink'

Signed-off-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Reviewed-by: Stephen Boyd &lt;sboyd@kernel.org&gt;
Signed-off-by: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Link: https://lore.kernel.org/r/20220519073330.7187-2-krzysztof.kozlowski@linaro.org
</pre>
</div>
</content>
</entry>
<entry>
<title>rpmsg: qcom: glink: replace strncpy() with strscpy_pad()</title>
<updated>2022-07-17T03:13:32+00:00</updated>
<author>
<name>Krzysztof Kozlowski</name>
<email>krzysztof.kozlowski@linaro.org</email>
</author>
<published>2022-05-19T07:33:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=766279a8f85df32345dbda03b102ca1ee3d5ddea'/>
<id>766279a8f85df32345dbda03b102ca1ee3d5ddea</id>
<content type='text'>
The use of strncpy() is considered deprecated for NUL-terminated
strings[1]. Replace strncpy() with strscpy_pad(), to keep existing
pad-behavior of strncpy, similarly to commit 08de420a8014 ("rpmsg:
glink: Replace strncpy() with strscpy_pad()").  This fixes W=1 warning:

  In function ‘qcom_glink_rx_close’,
    inlined from ‘qcom_glink_work’ at ../drivers/rpmsg/qcom_glink_native.c:1638:4:
  drivers/rpmsg/qcom_glink_native.c:1549:17: warning: ‘strncpy’ specified bound 32 equals destination size [-Wstringop-truncation]
   1549 |                 strncpy(chinfo.name, channel-&gt;name, sizeof(chinfo.name));

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings

Signed-off-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Reviewed-by: Stephen Boyd &lt;sboyd@kernel.org&gt;
Signed-off-by: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Link: https://lore.kernel.org/r/20220519073330.7187-1-krzysztof.kozlowski@linaro.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The use of strncpy() is considered deprecated for NUL-terminated
strings[1]. Replace strncpy() with strscpy_pad(), to keep existing
pad-behavior of strncpy, similarly to commit 08de420a8014 ("rpmsg:
glink: Replace strncpy() with strscpy_pad()").  This fixes W=1 warning:

  In function ‘qcom_glink_rx_close’,
    inlined from ‘qcom_glink_work’ at ../drivers/rpmsg/qcom_glink_native.c:1638:4:
  drivers/rpmsg/qcom_glink_native.c:1549:17: warning: ‘strncpy’ specified bound 32 equals destination size [-Wstringop-truncation]
   1549 |                 strncpy(chinfo.name, channel-&gt;name, sizeof(chinfo.name));

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings

Signed-off-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Reviewed-by: Stephen Boyd &lt;sboyd@kernel.org&gt;
Signed-off-by: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Link: https://lore.kernel.org/r/20220519073330.7187-1-krzysztof.kozlowski@linaro.org
</pre>
</div>
</content>
</entry>
<entry>
<title>rpmsg: Strcpy is not safe, use strscpy_pad() instead</title>
<updated>2022-06-24T17:37:00+00:00</updated>
<author>
<name>Saud Farooqui</name>
<email>farooqui_saud@hotmail.com</email>
</author>
<published>2022-06-23T09:20:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=99de6509c4135f1d1ceb98c42fa02d249b28b40f'/>
<id>99de6509c4135f1d1ceb98c42fa02d249b28b40f</id>
<content type='text'>
Replace strcpy() with strscpy_pad() for copying the rpmsg
device name in rpmsg_register_device_override().

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Saud Farooqui &lt;farooqui_saud@hotmail.com&gt;
Link: https://lore.kernel.org/r/PA4P189MB14210AA95DCA3715AFA7F4A68BB59@PA4P189MB1421.EURP189.PROD.OUTLOOK.COM
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Replace strcpy() with strscpy_pad() for copying the rpmsg
device name in rpmsg_register_device_override().

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Saud Farooqui &lt;farooqui_saud@hotmail.com&gt;
Link: https://lore.kernel.org/r/PA4P189MB14210AA95DCA3715AFA7F4A68BB59@PA4P189MB1421.EURP189.PROD.OUTLOOK.COM
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rpmsg: Fix possible refcount leak in rpmsg_register_device_override()</title>
<updated>2022-06-24T17:34:00+00:00</updated>
<author>
<name>Hangyu Hua</name>
<email>hbh25y@gmail.com</email>
</author>
<published>2022-06-24T02:41:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d7bd416d35121c95fe47330e09a5c04adbc5f928'/>
<id>d7bd416d35121c95fe47330e09a5c04adbc5f928</id>
<content type='text'>
rpmsg_register_device_override need to call put_device to free vch when
driver_set_override fails.

Fix this by adding a put_device() to the error path.

Fixes: bb17d110cbf2 ("rpmsg: Fix calling device_lock() on non-initialized device")
Reviewed-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Signed-off-by: Hangyu Hua &lt;hbh25y@gmail.com&gt;
Link: https://lore.kernel.org/r/20220624024120.11576-1-hbh25y@gmail.com
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
rpmsg_register_device_override need to call put_device to free vch when
driver_set_override fails.

Fix this by adding a put_device() to the error path.

Fixes: bb17d110cbf2 ("rpmsg: Fix calling device_lock() on non-initialized device")
Reviewed-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Signed-off-by: Hangyu Hua &lt;hbh25y@gmail.com&gt;
Link: https://lore.kernel.org/r/20220624024120.11576-1-hbh25y@gmail.com
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rpmsg: Fix parameter naming for announce_create/destroy ops</title>
<updated>2022-06-24T16:58:12+00:00</updated>
<author>
<name>Arnaud Pouliquen</name>
<email>arnaud.pouliquen@foss.st.com</email>
</author>
<published>2022-04-25T07:17:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=416b992b05c94cd691a1909f10e333f02cb81e56'/>
<id>416b992b05c94cd691a1909f10e333f02cb81e56</id>
<content type='text'>
The parameter associated to the announce_create and
announce_destroy ops functions is not an endpoint but a rpmsg device.

Signed-off-by: Arnaud Pouliquen &lt;arnaud.pouliquen@foss.st.com&gt;
Link: https://lore.kernel.org/r/20220425071723.774050-1-arnaud.pouliquen@foss.st.com
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The parameter associated to the announce_create and
announce_destroy ops functions is not an endpoint but a rpmsg device.

Signed-off-by: Arnaud Pouliquen &lt;arnaud.pouliquen@foss.st.com&gt;
Link: https://lore.kernel.org/r/20220425071723.774050-1-arnaud.pouliquen@foss.st.com
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rpmsg: mtk_rpmsg: Fix circular locking dependency</title>
<updated>2022-06-14T22:41:10+00:00</updated>
<author>
<name>AngeloGioacchino Del Regno</name>
<email>angelogioacchino.delregno@collabora.com</email>
</author>
<published>2022-05-25T09:12:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=353d9214682e65c55cdffad8c82139a3321c5f13'/>
<id>353d9214682e65c55cdffad8c82139a3321c5f13</id>
<content type='text'>
During execution of the worker that's used to register rpmsg devices
we are safely locking the channels mutex but, when creating a new
endpoint for such devices, we are registering a IPI on the SCP, which
then makes the SCP to trigger an interrupt, lock its own mutex and in
turn register more subdevices.
This creates a circular locking dependency situation, as the mtk_rpmsg
channels_lock will then depend on the SCP IPI lock.

[   15.447736] ======================================================
[   15.460158] WARNING: possible circular locking dependency detected
[   15.460161] 5.17.0-next-20220324+ #399 Not tainted
[   15.460165] ------------------------------------------------------
[   15.460166] kworker/0:3/155 is trying to acquire lock:
[   15.460170] ffff5b4d0eaf1308 (&amp;scp-&gt;ipi_desc[i].lock){+.+.}-{4:4}, at: scp_ipi_lock+0x34/0x50 [mtk_scp_ipi]
[   15.504958]
[]                but task is already holding lock:
[   15.504960] ffff5b4d0e8f1918 (&amp;mtk_subdev-&gt;channels_lock){+.+.}-{4:4}, at: mtk_register_device_work_function+0x50/0x1cc [mtk_rpmsg]
[   15.504978]
[]                which lock already depends on the new lock.

[   15.504980]
[]                the existing dependency chain (in reverse order) is:
[   15.504982]
[]               -&gt; #1 (&amp;mtk_subdev-&gt;channels_lock){+.+.}-{4:4}:
[   15.504990]        lock_acquire+0x68/0x84
[   15.504999]        __mutex_lock+0xa4/0x3e0
[   15.505007]        mutex_lock_nested+0x40/0x70
[   15.505012]        mtk_rpmsg_ns_cb+0xe4/0x134 [mtk_rpmsg]
[   15.641684]        mtk_rpmsg_ipi_handler+0x38/0x64 [mtk_rpmsg]
[   15.641693]        scp_ipi_handler+0xbc/0x180 [mtk_scp]
[   15.663905]        mt8192_scp_irq_handler+0x44/0xa4 [mtk_scp]
[   15.663915]        scp_irq_handler+0x6c/0xa0 [mtk_scp]
[   15.685779]        irq_thread_fn+0x34/0xa0
[   15.685785]        irq_thread+0x18c/0x240
[   15.685789]        kthread+0x104/0x110
[   15.709579]        ret_from_fork+0x10/0x20
[   15.709586]
[]               -&gt; #0 (&amp;scp-&gt;ipi_desc[i].lock){+.+.}-{4:4}:
[   15.731271]        __lock_acquire+0x11e4/0x1910
[   15.740367]        lock_acquire.part.0+0xd8/0x220
[   15.749813]        lock_acquire+0x68/0x84
[   15.757861]        __mutex_lock+0xa4/0x3e0
[   15.766084]        mutex_lock_nested+0x40/0x70
[   15.775006]        scp_ipi_lock+0x34/0x50 [mtk_scp_ipi]
[   15.785503]        scp_ipi_register+0x40/0xa4 [mtk_scp_ipi]
[   15.796697]        scp_register_ipi+0x1c/0x30 [mtk_scp]
[   15.807194]        mtk_rpmsg_create_ept+0xa0/0x108 [mtk_rpmsg]
[   15.818912]        rpmsg_create_ept+0x44/0x60
[   15.827660]        cros_ec_rpmsg_probe+0x15c/0x1f0
[   15.837282]        rpmsg_dev_probe+0x128/0x1d0
[   15.846203]        really_probe.part.0+0xa4/0x2a0
[   15.855649]        __driver_probe_device+0xa0/0x150
[   15.865443]        driver_probe_device+0x48/0x150
[   15.877157]        __device_attach_driver+0xc0/0x12c
[   15.889359]        bus_for_each_drv+0x80/0xe0
[   15.900330]        __device_attach+0xe4/0x190
[   15.911303]        device_initial_probe+0x1c/0x2c
[   15.922969]        bus_probe_device+0xa8/0xb0
[   15.933927]        device_add+0x3a8/0x8a0
[   15.944193]        device_register+0x28/0x40
[   15.954970]        rpmsg_register_device+0x5c/0xa0
[   15.966782]        mtk_register_device_work_function+0x148/0x1cc [mtk_rpmsg]
[   15.983146]        process_one_work+0x294/0x664
[   15.994458]        worker_thread+0x7c/0x45c
[   16.005069]        kthread+0x104/0x110
[   16.014789]        ret_from_fork+0x10/0x20
[   16.025201]
[]               other info that might help us debug this:

[   16.047769]  Possible unsafe locking scenario:

[   16.063942]        CPU0                    CPU1
[   16.075166]        ----                    ----
[   16.086376]   lock(&amp;mtk_subdev-&gt;channels_lock);
[   16.097592]                                lock(&amp;scp-&gt;ipi_desc[i].lock);
[   16.113188]                                lock(&amp;mtk_subdev-&gt;channels_lock);
[   16.129482]   lock(&amp;scp-&gt;ipi_desc[i].lock);
[   16.140020]
[]                *** DEADLOCK ***

[   16.158282] 4 locks held by kworker/0:3/155:
[   16.168978]  #0: ffff5b4d00008748 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1fc/0x664
[   16.190017]  #1: ffff80000953bdc8 ((work_completion)(&amp;mtk_subdev-&gt;register_work)){+.+.}-{0:0}, at: process_one_work+0x1fc/0x664
[   16.215269]  #2: ffff5b4d0e8f1918 (&amp;mtk_subdev-&gt;channels_lock){+.+.}-{4:4}, at: mtk_register_device_work_function+0x50/0x1cc [mtk_rpmsg]
[   16.242131]  #3: ffff5b4d05964190 (&amp;dev-&gt;mutex){....}-{4:4}, at: __device_attach+0x44/0x190

To solve this, simply unlock the channels_lock mutex before calling
mtk_rpmsg_register_device() and relock it right after, as safety is
still ensured by the locking mechanism that happens right after
through SCP.

Fixes: 7017996951fd ("rpmsg: add rpmsg support for mt8183 SCP.")
Signed-off-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Link: https://lore.kernel.org/r/20220525091201.14210-1-angelogioacchino.delregno@collabora.com
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
</content>
<content type='xhtml'>
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<pre>
During execution of the worker that's used to register rpmsg devices
we are safely locking the channels mutex but, when creating a new
endpoint for such devices, we are registering a IPI on the SCP, which
then makes the SCP to trigger an interrupt, lock its own mutex and in
turn register more subdevices.
This creates a circular locking dependency situation, as the mtk_rpmsg
channels_lock will then depend on the SCP IPI lock.

[   15.447736] ======================================================
[   15.460158] WARNING: possible circular locking dependency detected
[   15.460161] 5.17.0-next-20220324+ #399 Not tainted
[   15.460165] ------------------------------------------------------
[   15.460166] kworker/0:3/155 is trying to acquire lock:
[   15.460170] ffff5b4d0eaf1308 (&amp;scp-&gt;ipi_desc[i].lock){+.+.}-{4:4}, at: scp_ipi_lock+0x34/0x50 [mtk_scp_ipi]
[   15.504958]
[]                but task is already holding lock:
[   15.504960] ffff5b4d0e8f1918 (&amp;mtk_subdev-&gt;channels_lock){+.+.}-{4:4}, at: mtk_register_device_work_function+0x50/0x1cc [mtk_rpmsg]
[   15.504978]
[]                which lock already depends on the new lock.

[   15.504980]
[]                the existing dependency chain (in reverse order) is:
[   15.504982]
[]               -&gt; #1 (&amp;mtk_subdev-&gt;channels_lock){+.+.}-{4:4}:
[   15.504990]        lock_acquire+0x68/0x84
[   15.504999]        __mutex_lock+0xa4/0x3e0
[   15.505007]        mutex_lock_nested+0x40/0x70
[   15.505012]        mtk_rpmsg_ns_cb+0xe4/0x134 [mtk_rpmsg]
[   15.641684]        mtk_rpmsg_ipi_handler+0x38/0x64 [mtk_rpmsg]
[   15.641693]        scp_ipi_handler+0xbc/0x180 [mtk_scp]
[   15.663905]        mt8192_scp_irq_handler+0x44/0xa4 [mtk_scp]
[   15.663915]        scp_irq_handler+0x6c/0xa0 [mtk_scp]
[   15.685779]        irq_thread_fn+0x34/0xa0
[   15.685785]        irq_thread+0x18c/0x240
[   15.685789]        kthread+0x104/0x110
[   15.709579]        ret_from_fork+0x10/0x20
[   15.709586]
[]               -&gt; #0 (&amp;scp-&gt;ipi_desc[i].lock){+.+.}-{4:4}:
[   15.731271]        __lock_acquire+0x11e4/0x1910
[   15.740367]        lock_acquire.part.0+0xd8/0x220
[   15.749813]        lock_acquire+0x68/0x84
[   15.757861]        __mutex_lock+0xa4/0x3e0
[   15.766084]        mutex_lock_nested+0x40/0x70
[   15.775006]        scp_ipi_lock+0x34/0x50 [mtk_scp_ipi]
[   15.785503]        scp_ipi_register+0x40/0xa4 [mtk_scp_ipi]
[   15.796697]        scp_register_ipi+0x1c/0x30 [mtk_scp]
[   15.807194]        mtk_rpmsg_create_ept+0xa0/0x108 [mtk_rpmsg]
[   15.818912]        rpmsg_create_ept+0x44/0x60
[   15.827660]        cros_ec_rpmsg_probe+0x15c/0x1f0
[   15.837282]        rpmsg_dev_probe+0x128/0x1d0
[   15.846203]        really_probe.part.0+0xa4/0x2a0
[   15.855649]        __driver_probe_device+0xa0/0x150
[   15.865443]        driver_probe_device+0x48/0x150
[   15.877157]        __device_attach_driver+0xc0/0x12c
[   15.889359]        bus_for_each_drv+0x80/0xe0
[   15.900330]        __device_attach+0xe4/0x190
[   15.911303]        device_initial_probe+0x1c/0x2c
[   15.922969]        bus_probe_device+0xa8/0xb0
[   15.933927]        device_add+0x3a8/0x8a0
[   15.944193]        device_register+0x28/0x40
[   15.954970]        rpmsg_register_device+0x5c/0xa0
[   15.966782]        mtk_register_device_work_function+0x148/0x1cc [mtk_rpmsg]
[   15.983146]        process_one_work+0x294/0x664
[   15.994458]        worker_thread+0x7c/0x45c
[   16.005069]        kthread+0x104/0x110
[   16.014789]        ret_from_fork+0x10/0x20
[   16.025201]
[]               other info that might help us debug this:

[   16.047769]  Possible unsafe locking scenario:

[   16.063942]        CPU0                    CPU1
[   16.075166]        ----                    ----
[   16.086376]   lock(&amp;mtk_subdev-&gt;channels_lock);
[   16.097592]                                lock(&amp;scp-&gt;ipi_desc[i].lock);
[   16.113188]                                lock(&amp;mtk_subdev-&gt;channels_lock);
[   16.129482]   lock(&amp;scp-&gt;ipi_desc[i].lock);
[   16.140020]
[]                *** DEADLOCK ***

[   16.158282] 4 locks held by kworker/0:3/155:
[   16.168978]  #0: ffff5b4d00008748 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1fc/0x664
[   16.190017]  #1: ffff80000953bdc8 ((work_completion)(&amp;mtk_subdev-&gt;register_work)){+.+.}-{0:0}, at: process_one_work+0x1fc/0x664
[   16.215269]  #2: ffff5b4d0e8f1918 (&amp;mtk_subdev-&gt;channels_lock){+.+.}-{4:4}, at: mtk_register_device_work_function+0x50/0x1cc [mtk_rpmsg]
[   16.242131]  #3: ffff5b4d05964190 (&amp;dev-&gt;mutex){....}-{4:4}, at: __device_attach+0x44/0x190

To solve this, simply unlock the channels_lock mutex before calling
mtk_rpmsg_register_device() and relock it right after, as safety is
still ensured by the locking mechanism that happens right after
through SCP.

Fixes: 7017996951fd ("rpmsg: add rpmsg support for mt8183 SCP.")
Signed-off-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Link: https://lore.kernel.org/r/20220525091201.14210-1-angelogioacchino.delregno@collabora.com
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rpmsg: char: Add mutex protection for rpmsg_eptdev_open()</title>
<updated>2022-06-14T20:58:10+00:00</updated>
<author>
<name>Shengjiu Wang</name>
<email>shengjiu.wang@nxp.com</email>
</author>
<published>2022-05-21T03:35:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=abe13e9a561d6b3e82b21362c0d6dd3ecd8a5b13'/>
<id>abe13e9a561d6b3e82b21362c0d6dd3ecd8a5b13</id>
<content type='text'>
There is no mutex protection for rpmsg_eptdev_open(),
especially for eptdev-&gt;ept read and write operation.
It may cause issues when multiple instances call
rpmsg_eptdev_open() in parallel,the return state
may be success or EBUSY.

Fixes: 964e8bedd5a1 ("rpmsg: char: Return an error if device already open")
Signed-off-by: Shengjiu Wang &lt;shengjiu.wang@nxp.com&gt;
Link: https://lore.kernel.org/r/1653104105-16779-1-git-send-email-shengjiu.wang@nxp.com
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There is no mutex protection for rpmsg_eptdev_open(),
especially for eptdev-&gt;ept read and write operation.
It may cause issues when multiple instances call
rpmsg_eptdev_open() in parallel,the return state
may be success or EBUSY.

Fixes: 964e8bedd5a1 ("rpmsg: char: Return an error if device already open")
Signed-off-by: Shengjiu Wang &lt;shengjiu.wang@nxp.com&gt;
Link: https://lore.kernel.org/r/1653104105-16779-1-git-send-email-shengjiu.wang@nxp.com
Signed-off-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
</pre>
</div>
</content>
</entry>
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