<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/dma, branch v6.1.76</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>dmaengine: fix NULL pointer in channel unregistration function</title>
<updated>2024-02-01T00:17:00+00:00</updated>
<author>
<name>Amelie Delaunay</name>
<email>amelie.delaunay@foss.st.com</email>
</author>
<published>2023-12-13T16:04:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2ab32986a0b9e329eb7f8f04dd57cc127f797c08'/>
<id>2ab32986a0b9e329eb7f8f04dd57cc127f797c08</id>
<content type='text'>
[ Upstream commit f5c24d94512f1b288262beda4d3dcb9629222fc7 ]

__dma_async_device_channel_register() can fail. In case of failure,
chan-&gt;local is freed (with free_percpu()), and chan-&gt;local is nullified.
When dma_async_device_unregister() is called (because of managed API or
intentionally by DMA controller driver), channels are unconditionally
unregistered, leading to this NULL pointer:
[    1.318693] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000d0
[...]
[    1.484499] Call trace:
[    1.486930]  device_del+0x40/0x394
[    1.490314]  device_unregister+0x20/0x7c
[    1.494220]  __dma_async_device_channel_unregister+0x68/0xc0

Look at dma_async_device_register() function error path, channel device
unregistration is done only if chan-&gt;local is not NULL.

Then add the same condition at the beginning of
__dma_async_device_channel_unregister() function, to avoid NULL pointer
issue whatever the API used to reach this function.

Fixes: d2fb0a043838 ("dmaengine: break out channel registration")
Signed-off-by: Amelie Delaunay &lt;amelie.delaunay@foss.st.com&gt;
Reviewed-by: Dave Jiang &lt;dave.jiang@intel.com&gt;
Link: https://lore.kernel.org/r/20231213160452.2598073-1-amelie.delaunay@foss.st.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit f5c24d94512f1b288262beda4d3dcb9629222fc7 ]

__dma_async_device_channel_register() can fail. In case of failure,
chan-&gt;local is freed (with free_percpu()), and chan-&gt;local is nullified.
When dma_async_device_unregister() is called (because of managed API or
intentionally by DMA controller driver), channels are unconditionally
unregistered, leading to this NULL pointer:
[    1.318693] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000d0
[...]
[    1.484499] Call trace:
[    1.486930]  device_del+0x40/0x394
[    1.490314]  device_unregister+0x20/0x7c
[    1.494220]  __dma_async_device_channel_unregister+0x68/0xc0

Look at dma_async_device_register() function error path, channel device
unregistration is done only if chan-&gt;local is not NULL.

Then add the same condition at the beginning of
__dma_async_device_channel_unregister() function, to avoid NULL pointer
issue whatever the API used to reach this function.

Fixes: d2fb0a043838 ("dmaengine: break out channel registration")
Signed-off-by: Amelie Delaunay &lt;amelie.delaunay@foss.st.com&gt;
Reviewed-by: Dave Jiang &lt;dave.jiang@intel.com&gt;
Link: https://lore.kernel.org/r/20231213160452.2598073-1-amelie.delaunay@foss.st.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dmaengine: stm32-dma: avoid bitfield overflow assertion</title>
<updated>2023-12-20T16:00:25+00:00</updated>
<author>
<name>Amelie Delaunay</name>
<email>amelie.delaunay@foss.st.com</email>
</author>
<published>2023-11-06T13:48:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=40f3ad769ec8eb8a0cf62ee8eae16f41aae16363'/>
<id>40f3ad769ec8eb8a0cf62ee8eae16f41aae16363</id>
<content type='text'>
commit 54bed6bafa0f38daf9697af50e3aff5ff1354fe1 upstream.

stm32_dma_get_burst() returns a negative error for invalid input, which
gets turned into a large u32 value in stm32_dma_prep_dma_memcpy() that
in turn triggers an assertion because it does not fit into a two-bit field:
drivers/dma/stm32-dma.c: In function 'stm32_dma_prep_dma_memcpy':
include/linux/compiler_types.h:354:38: error: call to '__compiletime_assert_282' declared with attribute error: FIELD_PREP: value too large for the field
     _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
                                         ^
   include/linux/compiler_types.h:335:4: note: in definition of macro '__compiletime_assert'
       prefix ## suffix();    \
       ^~~~~~
   include/linux/compiler_types.h:354:2: note: in expansion of macro '_compiletime_assert'
     _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
     ^~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert'
    #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
                                        ^~~~~~~~~~~~~~~~~~
   include/linux/bitfield.h:68:3: note: in expansion of macro 'BUILD_BUG_ON_MSG'
      BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ?  \
      ^~~~~~~~~~~~~~~~
   include/linux/bitfield.h:114:3: note: in expansion of macro '__BF_FIELD_CHECK'
      __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: "); \
      ^~~~~~~~~~~~~~~~
   drivers/dma/stm32-dma.c:1237:4: note: in expansion of macro 'FIELD_PREP'
       FIELD_PREP(STM32_DMA_SCR_PBURST_MASK, dma_burst) |
       ^~~~~~~~~~

As an easy workaround, assume the error can happen, so try to handle this
by failing stm32_dma_prep_dma_memcpy() before the assertion. It replicates
what is done in stm32_dma_set_xfer_param() where stm32_dma_get_burst() is
also used.

Fixes: 1c32d6c37cc2 ("dmaengine: stm32-dma: use bitfield helpers")
Fixes: a2b6103b7a8a ("dmaengine: stm32-dma: Improve memory burst management")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Amelie Delaunay &lt;amelie.delaunay@foss.st.com&gt;
Cc: stable@vger.kernel.org
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/oe-kbuild-all/202311060135.Q9eMnpCL-lkp@intel.com/
Link: https://lore.kernel.org/r/20231106134832.1470305-1-amelie.delaunay@foss.st.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 54bed6bafa0f38daf9697af50e3aff5ff1354fe1 upstream.

stm32_dma_get_burst() returns a negative error for invalid input, which
gets turned into a large u32 value in stm32_dma_prep_dma_memcpy() that
in turn triggers an assertion because it does not fit into a two-bit field:
drivers/dma/stm32-dma.c: In function 'stm32_dma_prep_dma_memcpy':
include/linux/compiler_types.h:354:38: error: call to '__compiletime_assert_282' declared with attribute error: FIELD_PREP: value too large for the field
     _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
                                         ^
   include/linux/compiler_types.h:335:4: note: in definition of macro '__compiletime_assert'
       prefix ## suffix();    \
       ^~~~~~
   include/linux/compiler_types.h:354:2: note: in expansion of macro '_compiletime_assert'
     _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
     ^~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert'
    #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
                                        ^~~~~~~~~~~~~~~~~~
   include/linux/bitfield.h:68:3: note: in expansion of macro 'BUILD_BUG_ON_MSG'
      BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ?  \
      ^~~~~~~~~~~~~~~~
   include/linux/bitfield.h:114:3: note: in expansion of macro '__BF_FIELD_CHECK'
      __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: "); \
      ^~~~~~~~~~~~~~~~
   drivers/dma/stm32-dma.c:1237:4: note: in expansion of macro 'FIELD_PREP'
       FIELD_PREP(STM32_DMA_SCR_PBURST_MASK, dma_burst) |
       ^~~~~~~~~~

As an easy workaround, assume the error can happen, so try to handle this
by failing stm32_dma_prep_dma_memcpy() before the assertion. It replicates
what is done in stm32_dma_set_xfer_param() where stm32_dma_get_burst() is
also used.

Fixes: 1c32d6c37cc2 ("dmaengine: stm32-dma: use bitfield helpers")
Fixes: a2b6103b7a8a ("dmaengine: stm32-dma: Improve memory burst management")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Amelie Delaunay &lt;amelie.delaunay@foss.st.com&gt;
Cc: stable@vger.kernel.org
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/oe-kbuild-all/202311060135.Q9eMnpCL-lkp@intel.com/
Link: https://lore.kernel.org/r/20231106134832.1470305-1-amelie.delaunay@foss.st.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dmaengine: stm32-mdma: correct desc prep when channel running</title>
<updated>2023-11-28T17:07:13+00:00</updated>
<author>
<name>Alain Volmat</name>
<email>alain.volmat@foss.st.com</email>
</author>
<published>2023-10-09T08:24:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7fc465d2653a0b9ff5d804d2139ca99f2c33656f'/>
<id>7fc465d2653a0b9ff5d804d2139ca99f2c33656f</id>
<content type='text'>
commit 03f25d53b145bc2f7ccc82fc04e4482ed734f524 upstream.

In case of the prep descriptor while the channel is already running, the
CCR register value stored into the channel could already have its EN bit
set.  This would lead to a bad transfer since, at start transfer time,
enabling the channel while other registers aren't yet properly set.
To avoid this, ensure to mask the CCR_EN bit when storing the ccr value
into the mdma channel structure.

Fixes: a4ffb13c8946 ("dmaengine: Add STM32 MDMA driver")
Signed-off-by: Alain Volmat &lt;alain.volmat@foss.st.com&gt;
Signed-off-by: Amelie Delaunay &lt;amelie.delaunay@foss.st.com&gt;
Cc: stable@vger.kernel.org
Tested-by: Alain Volmat &lt;alain.volmat@foss.st.com&gt;
Link: https://lore.kernel.org/r/20231009082450.452877-1-amelie.delaunay@foss.st.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 03f25d53b145bc2f7ccc82fc04e4482ed734f524 upstream.

In case of the prep descriptor while the channel is already running, the
CCR register value stored into the channel could already have its EN bit
set.  This would lead to a bad transfer since, at start transfer time,
enabling the channel while other registers aren't yet properly set.
To avoid this, ensure to mask the CCR_EN bit when storing the ccr value
into the mdma channel structure.

Fixes: a4ffb13c8946 ("dmaengine: Add STM32 MDMA driver")
Signed-off-by: Alain Volmat &lt;alain.volmat@foss.st.com&gt;
Signed-off-by: Amelie Delaunay &lt;amelie.delaunay@foss.st.com&gt;
Cc: stable@vger.kernel.org
Tested-by: Alain Volmat &lt;alain.volmat@foss.st.com&gt;
Link: https://lore.kernel.org/r/20231009082450.452877-1-amelie.delaunay@foss.st.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dmaengine: pxa_dma: Remove an erroneous BUG_ON() in pxad_free_desc()</title>
<updated>2023-11-20T10:52:10+00:00</updated>
<author>
<name>Christophe JAILLET</name>
<email>christophe.jaillet@wanadoo.fr</email>
</author>
<published>2023-10-07T11:13:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7b863b8bcd678e88da0e0cf8b6ca86d431b88812'/>
<id>7b863b8bcd678e88da0e0cf8b6ca86d431b88812</id>
<content type='text'>
[ Upstream commit 83c761f568733277ce1f7eb9dc9e890649c29a8c ]

If pxad_alloc_desc() fails on the first dma_pool_alloc() call, then
sw_desc-&gt;nb_desc is zero.
In such a case pxad_free_desc() is called and it will BUG_ON().

Remove this erroneous BUG_ON().

It is also useless, because if "sw_desc-&gt;nb_desc == 0", then, on the first
iteration of the for loop, i is -1 and the loop will not be executed.
(both i and sw_desc-&gt;nb_desc are 'int')

Fixes: a57e16cf0333 ("dmaengine: pxa: add pxa dmaengine driver")
Signed-off-by: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Link: https://lore.kernel.org/r/c8fc5563c9593c914fde41f0f7d1489a21b45a9a.1696676782.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 83c761f568733277ce1f7eb9dc9e890649c29a8c ]

If pxad_alloc_desc() fails on the first dma_pool_alloc() call, then
sw_desc-&gt;nb_desc is zero.
In such a case pxad_free_desc() is called and it will BUG_ON().

Remove this erroneous BUG_ON().

It is also useless, because if "sw_desc-&gt;nb_desc == 0", then, on the first
iteration of the for loop, i is -1 and the loop will not be executed.
(both i and sw_desc-&gt;nb_desc are 'int')

Fixes: a57e16cf0333 ("dmaengine: pxa: add pxa dmaengine driver")
Signed-off-by: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Link: https://lore.kernel.org/r/c8fc5563c9593c914fde41f0f7d1489a21b45a9a.1696676782.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dmaengine: ti: edma: handle irq_of_parse_and_map() errors</title>
<updated>2023-11-20T10:52:10+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@linaro.org</email>
</author>
<published>2023-09-15T12:59:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fc968818d547fd2f47ea992405575a57af9b5420'/>
<id>fc968818d547fd2f47ea992405575a57af9b5420</id>
<content type='text'>
[ Upstream commit 14f6d317913f634920a640e9047aa2e66f5bdcb7 ]

Zero is not a valid IRQ for in-kernel code and the irq_of_parse_and_map()
function returns zero on error.  So this check for valid IRQs should only
accept values &gt; 0.

Fixes: 2b6b3b742019 ("ARM/dmaengine: edma: Merge the two drivers under drivers/dma/")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Acked-by: Peter Ujfalusi &lt;peter.ujfalusi@gmail.com&gt;
Link: https://lore.kernel.org/r/f15cb6a7-8449-4f79-98b6-34072f04edbc@moroto.mountain
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 14f6d317913f634920a640e9047aa2e66f5bdcb7 ]

Zero is not a valid IRQ for in-kernel code and the irq_of_parse_and_map()
function returns zero on error.  So this check for valid IRQs should only
accept values &gt; 0.

Fixes: 2b6b3b742019 ("ARM/dmaengine: edma: Merge the two drivers under drivers/dma/")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Acked-by: Peter Ujfalusi &lt;peter.ujfalusi@gmail.com&gt;
Link: https://lore.kernel.org/r/f15cb6a7-8449-4f79-98b6-34072f04edbc@moroto.mountain
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dmaengine: idxd: Register dsa_bus_type before registering idxd sub-drivers</title>
<updated>2023-11-20T10:52:10+00:00</updated>
<author>
<name>Fenghua Yu</name>
<email>fenghua.yu@intel.com</email>
</author>
<published>2023-09-24T16:22:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0806a6afe155828420fe5b612ebf0bb1b92f72c3'/>
<id>0806a6afe155828420fe5b612ebf0bb1b92f72c3</id>
<content type='text'>
[ Upstream commit 88928addeec577386e8c83b48b5bc24d28ba97fd ]

idxd sub-drivers belong to bus dsa_bus_type. Thus, dsa_bus_type must be
registered in dsa bus init before idxd drivers can be registered.

But the order is wrong when both idxd and idxd_bus are builtin drivers.
In this case, idxd driver is compiled and linked before idxd_bus driver.
Since the initcall order is determined by the link order, idxd sub-drivers
are registered in idxd initcall before dsa_bus_type is registered
in idxd_bus initcall. idxd initcall fails:

[   21.562803] calling  idxd_init_module+0x0/0x110 @ 1
[   21.570761] Driver 'idxd' was unable to register with bus_type 'dsa' because the bus was not initialized.
[   21.586475] initcall idxd_init_module+0x0/0x110 returned -22 after 15717 usecs
[   21.597178] calling  dsa_bus_init+0x0/0x20 @ 1

To fix the issue, compile and link idxd_bus driver before idxd driver
to ensure the right registration order.

Fixes: d9e5481fca74 ("dmaengine: dsa: move dsa_bus_type out of idxd driver to standalone")
Reported-by: Michael Prinke &lt;michael.prinke@intel.com&gt;
Signed-off-by: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Reviewed-by: Dave Jiang &lt;dave.jiang@intel.com&gt;
Reviewed-by: Lijun Pan &lt;lijun.pan@intel.com&gt;
Tested-by: Lijun Pan &lt;lijun.pan@intel.com&gt;
Link: https://lore.kernel.org/r/20230924162232.1409454-1-fenghua.yu@intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 88928addeec577386e8c83b48b5bc24d28ba97fd ]

idxd sub-drivers belong to bus dsa_bus_type. Thus, dsa_bus_type must be
registered in dsa bus init before idxd drivers can be registered.

But the order is wrong when both idxd and idxd_bus are builtin drivers.
In this case, idxd driver is compiled and linked before idxd_bus driver.
Since the initcall order is determined by the link order, idxd sub-drivers
are registered in idxd initcall before dsa_bus_type is registered
in idxd_bus initcall. idxd initcall fails:

[   21.562803] calling  idxd_init_module+0x0/0x110 @ 1
[   21.570761] Driver 'idxd' was unable to register with bus_type 'dsa' because the bus was not initialized.
[   21.586475] initcall idxd_init_module+0x0/0x110 returned -22 after 15717 usecs
[   21.597178] calling  dsa_bus_init+0x0/0x20 @ 1

To fix the issue, compile and link idxd_bus driver before idxd driver
to ensure the right registration order.

Fixes: d9e5481fca74 ("dmaengine: dsa: move dsa_bus_type out of idxd driver to standalone")
Reported-by: Michael Prinke &lt;michael.prinke@intel.com&gt;
Signed-off-by: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Reviewed-by: Dave Jiang &lt;dave.jiang@intel.com&gt;
Reviewed-by: Lijun Pan &lt;lijun.pan@intel.com&gt;
Tested-by: Lijun Pan &lt;lijun.pan@intel.com&gt;
Link: https://lore.kernel.org/r/20230924162232.1409454-1-fenghua.yu@intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dmaengine: ste_dma40: Fix PM disable depth imbalance in d40_probe</title>
<updated>2023-11-08T13:10:58+00:00</updated>
<author>
<name>Zhang Shurong</name>
<email>zhang_shurong@foxmail.com</email>
</author>
<published>2023-10-05T14:28:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=96c7aac8d8049f29e2588c7a7c329cc7a7836566'/>
<id>96c7aac8d8049f29e2588c7a7c329cc7a7836566</id>
<content type='text'>
[ Upstream commit 0618c077a8c20e8c81e367988f70f7e32bb5a717 ]

The pm_runtime_enable will increase power disable depth. Thus
a pairing decrement is needed on the error handling path to
keep it balanced according to context.
We fix it by calling pm_runtime_disable when error returns.

Signed-off-by: Zhang Shurong &lt;zhang_shurong@foxmail.com&gt;
Reviewed-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Link: https://lore.kernel.org/r/tencent_DD2D371DB5925B4B602B1E1D0A5FA88F1208@qq.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 0618c077a8c20e8c81e367988f70f7e32bb5a717 ]

The pm_runtime_enable will increase power disable depth. Thus
a pairing decrement is needed on the error handling path to
keep it balanced according to context.
We fix it by calling pm_runtime_disable when error returns.

Signed-off-by: Zhang Shurong &lt;zhang_shurong@foxmail.com&gt;
Reviewed-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Link: https://lore.kernel.org/r/tencent_DD2D371DB5925B4B602B1E1D0A5FA88F1208@qq.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dmaengine: mediatek: Fix deadlock caused by synchronize_irq()</title>
<updated>2023-10-19T21:08:58+00:00</updated>
<author>
<name>Duoming Zhou</name>
<email>duoming@zju.edu.cn</email>
</author>
<published>2023-08-06T03:25:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9a995e11b23f4afb4fe50e7d4d420e3ddcaa35a1'/>
<id>9a995e11b23f4afb4fe50e7d4d420e3ddcaa35a1</id>
<content type='text'>
[ Upstream commit 01f1ae2733e2bb4de92fefcea5fda847d92aede1 ]

The synchronize_irq(c-&gt;irq) will not return until the IRQ handler
mtk_uart_apdma_irq_handler() is completed. If the synchronize_irq()
holds a spin_lock and waits the IRQ handler to complete, but the
IRQ handler also needs the same spin_lock. The deadlock will happen.
The process is shown below:

          cpu0                        cpu1
mtk_uart_apdma_device_pause() | mtk_uart_apdma_irq_handler()
  spin_lock_irqsave()         |
                              |   spin_lock_irqsave()
  //hold the lock to wait     |
  synchronize_irq()           |

This patch reorders the synchronize_irq(c-&gt;irq) outside the spin_lock
in order to mitigate the bug.

Fixes: 9135408c3ace ("dmaengine: mediatek: Add MediaTek UART APDMA support")
Signed-off-by: Duoming Zhou &lt;duoming@zju.edu.cn&gt;
Reviewed-by: Eugen Hristev &lt;eugen.hristev@collabora.com&gt;
Link: https://lore.kernel.org/r/20230806032511.45263-1-duoming@zju.edu.cn
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 01f1ae2733e2bb4de92fefcea5fda847d92aede1 ]

The synchronize_irq(c-&gt;irq) will not return until the IRQ handler
mtk_uart_apdma_irq_handler() is completed. If the synchronize_irq()
holds a spin_lock and waits the IRQ handler to complete, but the
IRQ handler also needs the same spin_lock. The deadlock will happen.
The process is shown below:

          cpu0                        cpu1
mtk_uart_apdma_device_pause() | mtk_uart_apdma_irq_handler()
  spin_lock_irqsave()         |
                              |   spin_lock_irqsave()
  //hold the lock to wait     |
  synchronize_irq()           |

This patch reorders the synchronize_irq(c-&gt;irq) outside the spin_lock
in order to mitigate the bug.

Fixes: 9135408c3ace ("dmaengine: mediatek: Add MediaTek UART APDMA support")
Signed-off-by: Duoming Zhou &lt;duoming@zju.edu.cn&gt;
Reviewed-by: Eugen Hristev &lt;eugen.hristev@collabora.com&gt;
Link: https://lore.kernel.org/r/20230806032511.45263-1-duoming@zju.edu.cn
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dmaengine: idxd: use spin_lock_irqsave before wait_event_lock_irq</title>
<updated>2023-10-19T21:08:58+00:00</updated>
<author>
<name>Rex Zhang</name>
<email>rex.zhang@intel.com</email>
</author>
<published>2023-09-16T06:06:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=01b19fc6621d2b10d2433b1f0259f5745e403cd9'/>
<id>01b19fc6621d2b10d2433b1f0259f5745e403cd9</id>
<content type='text'>
[ Upstream commit c0409dd3d151f661e7e57b901a81a02565df163c ]

In idxd_cmd_exec(), wait_event_lock_irq() explicitly calls
spin_unlock_irq()/spin_lock_irq(). If the interrupt is on before entering
wait_event_lock_irq(), it will become off status after
wait_event_lock_irq() is called. Later, wait_for_completion() may go to
sleep but irq is disabled. The scenario is warned in might_sleep().

Fix it by using spin_lock_irqsave() instead of the primitive spin_lock()
to save the irq status before entering wait_event_lock_irq() and using
spin_unlock_irqrestore() instead of the primitive spin_unlock() to restore
the irq status before entering wait_for_completion().

Before the change:
idxd_cmd_exec() {
interrupt is on
spin_lock()                        // interrupt is on
	wait_event_lock_irq()
		spin_unlock_irq()  // interrupt is enabled
		...
		spin_lock_irq()    // interrupt is disabled
spin_unlock()                      // interrupt is still disabled
wait_for_completion()              // report "BUG: sleeping function
				   // called from invalid context...
				   // in_atomic() irqs_disabled()"
}

After applying spin_lock_irqsave():
idxd_cmd_exec() {
interrupt is on
spin_lock_irqsave()                // save the on state
				   // interrupt is disabled
	wait_event_lock_irq()
		spin_unlock_irq()  // interrupt is enabled
		...
		spin_lock_irq()    // interrupt is disabled
spin_unlock_irqrestore()           // interrupt is restored to on
wait_for_completion()              // No Call trace
}

Fixes: f9f4082dbc56 ("dmaengine: idxd: remove interrupt disable for cmd_lock")
Signed-off-by: Rex Zhang &lt;rex.zhang@intel.com&gt;
Signed-off-by: Lijun Pan &lt;lijun.pan@intel.com&gt;
Reviewed-by: Dave Jiang &lt;dave.jiang@intel.com&gt;
Reviewed-by: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Link: https://lore.kernel.org/r/20230916060619.3744220-1-rex.zhang@intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit c0409dd3d151f661e7e57b901a81a02565df163c ]

In idxd_cmd_exec(), wait_event_lock_irq() explicitly calls
spin_unlock_irq()/spin_lock_irq(). If the interrupt is on before entering
wait_event_lock_irq(), it will become off status after
wait_event_lock_irq() is called. Later, wait_for_completion() may go to
sleep but irq is disabled. The scenario is warned in might_sleep().

Fix it by using spin_lock_irqsave() instead of the primitive spin_lock()
to save the irq status before entering wait_event_lock_irq() and using
spin_unlock_irqrestore() instead of the primitive spin_unlock() to restore
the irq status before entering wait_for_completion().

Before the change:
idxd_cmd_exec() {
interrupt is on
spin_lock()                        // interrupt is on
	wait_event_lock_irq()
		spin_unlock_irq()  // interrupt is enabled
		...
		spin_lock_irq()    // interrupt is disabled
spin_unlock()                      // interrupt is still disabled
wait_for_completion()              // report "BUG: sleeping function
				   // called from invalid context...
				   // in_atomic() irqs_disabled()"
}

After applying spin_lock_irqsave():
idxd_cmd_exec() {
interrupt is on
spin_lock_irqsave()                // save the on state
				   // interrupt is disabled
	wait_event_lock_irq()
		spin_unlock_irq()  // interrupt is enabled
		...
		spin_lock_irq()    // interrupt is disabled
spin_unlock_irqrestore()           // interrupt is restored to on
wait_for_completion()              // No Call trace
}

Fixes: f9f4082dbc56 ("dmaengine: idxd: remove interrupt disable for cmd_lock")
Signed-off-by: Rex Zhang &lt;rex.zhang@intel.com&gt;
Signed-off-by: Lijun Pan &lt;lijun.pan@intel.com&gt;
Reviewed-by: Dave Jiang &lt;dave.jiang@intel.com&gt;
Reviewed-by: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Link: https://lore.kernel.org/r/20230916060619.3744220-1-rex.zhang@intel.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dmaengine: stm32-mdma: set in_flight_bytes in case CRQA flag is set</title>
<updated>2023-10-19T21:08:54+00:00</updated>
<author>
<name>Amelie Delaunay</name>
<email>amelie.delaunay@foss.st.com</email>
</author>
<published>2023-10-04T16:35:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f049b10affc5aea48ba300a926df1b527e297686'/>
<id>f049b10affc5aea48ba300a926df1b527e297686</id>
<content type='text'>
commit 584970421725b7805db84714b857851fdf7203a9 upstream.

CRQA flag is set by hardware when the channel request become active and
the channel is enabled. It is cleared by hardware, when the channel request
is completed.
So when it is set, it means MDMA is transferring bytes.
This information is useful in case of STM32 DMA and MDMA chaining,
especially when the user pauses DMA before stopping it, to trig one last
MDMA transfer to get the latest bytes of the SRAM buffer to the
destination buffer.
STM32 DCMI driver can then use this to know if the last MDMA transfer in
case of chaining is done.

Fixes: 696874322771 ("dmaengine: stm32-mdma: add support to be triggered by STM32 DMA")
Signed-off-by: Amelie Delaunay &lt;amelie.delaunay@foss.st.com&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231004163531.2864160-3-amelie.delaunay@foss.st.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 584970421725b7805db84714b857851fdf7203a9 upstream.

CRQA flag is set by hardware when the channel request become active and
the channel is enabled. It is cleared by hardware, when the channel request
is completed.
So when it is set, it means MDMA is transferring bytes.
This information is useful in case of STM32 DMA and MDMA chaining,
especially when the user pauses DMA before stopping it, to trig one last
MDMA transfer to get the latest bytes of the SRAM buffer to the
destination buffer.
STM32 DCMI driver can then use this to know if the last MDMA transfer in
case of chaining is done.

Fixes: 696874322771 ("dmaengine: stm32-mdma: add support to be triggered by STM32 DMA")
Signed-off-by: Amelie Delaunay &lt;amelie.delaunay@foss.st.com&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231004163531.2864160-3-amelie.delaunay@foss.st.com
Signed-off-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
