<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/spi, branch v4.4.185</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>spi: bitbang: Fix NULL pointer dereference in spi_unregister_master</title>
<updated>2019-07-10T07:56:39+00:00</updated>
<author>
<name>YueHaibing</name>
<email>yuehaibing@huawei.com</email>
</author>
<published>2019-05-16T07:56:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=05d6e618f64b877f6db17173f31063d51d023b81'/>
<id>05d6e618f64b877f6db17173f31063d51d023b81</id>
<content type='text'>
[ Upstream commit 5caaf29af5ca82d5da8bc1d0ad07d9e664ccf1d8 ]

If spi_register_master fails in spi_bitbang_start
because device_add failure, We should return the
error code other than 0, otherwise calling
spi_bitbang_stop may trigger NULL pointer dereference
like this:

BUG: KASAN: null-ptr-deref in __list_del_entry_valid+0x45/0xd0
Read of size 8 at addr 0000000000000000 by task syz-executor.0/3661

CPU: 0 PID: 3661 Comm: syz-executor.0 Not tainted 5.1.0+ #28
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
 dump_stack+0xa9/0x10e
 ? __list_del_entry_valid+0x45/0xd0
 ? __list_del_entry_valid+0x45/0xd0
 __kasan_report+0x171/0x18d
 ? __list_del_entry_valid+0x45/0xd0
 kasan_report+0xe/0x20
 __list_del_entry_valid+0x45/0xd0
 spi_unregister_controller+0x99/0x1b0
 spi_lm70llp_attach+0x3ae/0x4b0 [spi_lm70llp]
 ? 0xffffffffc1128000
 ? klist_next+0x131/0x1e0
 ? driver_detach+0x40/0x40 [parport]
 port_check+0x3b/0x50 [parport]
 bus_for_each_dev+0x115/0x180
 ? subsys_dev_iter_exit+0x20/0x20
 __parport_register_driver+0x1f0/0x210 [parport]
 ? 0xffffffffc1150000
 do_one_initcall+0xb9/0x3b5
 ? perf_trace_initcall_level+0x270/0x270
 ? kasan_unpoison_shadow+0x30/0x40
 ? kasan_unpoison_shadow+0x30/0x40
 do_init_module+0xe0/0x330
 load_module+0x38eb/0x4270
 ? module_frob_arch_sections+0x20/0x20
 ? kernel_read_file+0x188/0x3f0
 ? find_held_lock+0x6d/0xd0
 ? fput_many+0x1a/0xe0
 ? __do_sys_finit_module+0x162/0x190
 __do_sys_finit_module+0x162/0x190
 ? __ia32_sys_init_module+0x40/0x40
 ? __mutex_unlock_slowpath+0xb4/0x3f0
 ? wait_for_completion+0x240/0x240
 ? vfs_write+0x160/0x2a0
 ? lockdep_hardirqs_off+0xb5/0x100
 ? mark_held_locks+0x1a/0x90
 ? do_syscall_64+0x14/0x2a0
 do_syscall_64+0x72/0x2a0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reported-by: Hulk Robot &lt;hulkci@huawei.com&gt;
Fixes: 702a4879ec33 ("spi: bitbang: Let spi_bitbang_start() take a reference to master")
Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Reviewed-by: Axel Lin &lt;axel.lin@ingics.com&gt;
Reviewed-by: Mukesh Ojha &lt;mojha@codeaurora.org&gt;
Signed-off-by: Mark Brown &lt;broonie@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 5caaf29af5ca82d5da8bc1d0ad07d9e664ccf1d8 ]

If spi_register_master fails in spi_bitbang_start
because device_add failure, We should return the
error code other than 0, otherwise calling
spi_bitbang_stop may trigger NULL pointer dereference
like this:

BUG: KASAN: null-ptr-deref in __list_del_entry_valid+0x45/0xd0
Read of size 8 at addr 0000000000000000 by task syz-executor.0/3661

CPU: 0 PID: 3661 Comm: syz-executor.0 Not tainted 5.1.0+ #28
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
 dump_stack+0xa9/0x10e
 ? __list_del_entry_valid+0x45/0xd0
 ? __list_del_entry_valid+0x45/0xd0
 __kasan_report+0x171/0x18d
 ? __list_del_entry_valid+0x45/0xd0
 kasan_report+0xe/0x20
 __list_del_entry_valid+0x45/0xd0
 spi_unregister_controller+0x99/0x1b0
 spi_lm70llp_attach+0x3ae/0x4b0 [spi_lm70llp]
 ? 0xffffffffc1128000
 ? klist_next+0x131/0x1e0
 ? driver_detach+0x40/0x40 [parport]
 port_check+0x3b/0x50 [parport]
 bus_for_each_dev+0x115/0x180
 ? subsys_dev_iter_exit+0x20/0x20
 __parport_register_driver+0x1f0/0x210 [parport]
 ? 0xffffffffc1150000
 do_one_initcall+0xb9/0x3b5
 ? perf_trace_initcall_level+0x270/0x270
 ? kasan_unpoison_shadow+0x30/0x40
 ? kasan_unpoison_shadow+0x30/0x40
 do_init_module+0xe0/0x330
 load_module+0x38eb/0x4270
 ? module_frob_arch_sections+0x20/0x20
 ? kernel_read_file+0x188/0x3f0
 ? find_held_lock+0x6d/0xd0
 ? fput_many+0x1a/0xe0
 ? __do_sys_finit_module+0x162/0x190
 __do_sys_finit_module+0x162/0x190
 ? __ia32_sys_init_module+0x40/0x40
 ? __mutex_unlock_slowpath+0xb4/0x3f0
 ? wait_for_completion+0x240/0x240
 ? vfs_write+0x160/0x2a0
 ? lockdep_hardirqs_off+0xb5/0x100
 ? mark_held_locks+0x1a/0x90
 ? do_syscall_64+0x14/0x2a0
 do_syscall_64+0x72/0x2a0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reported-by: Hulk Robot &lt;hulkci@huawei.com&gt;
Fixes: 702a4879ec33 ("spi: bitbang: Let spi_bitbang_start() take a reference to master")
Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Reviewed-by: Axel Lin &lt;axel.lin@ingics.com&gt;
Reviewed-by: Mukesh Ojha &lt;mojha@codeaurora.org&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dmaengine: idma64: Use actual device for DMA transfers</title>
<updated>2019-06-22T06:18:21+00:00</updated>
<author>
<name>Andy Shevchenko</name>
<email>andriy.shevchenko@linux.intel.com</email>
</author>
<published>2019-03-18T15:39:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d24e22cde8b3ee7d56af9038eb821ca8f7478109'/>
<id>d24e22cde8b3ee7d56af9038eb821ca8f7478109</id>
<content type='text'>
[ Upstream commit 5ba846b1ee0792f5a596b9b0b86d6e8cdebfab06 ]

Intel IOMMU, when enabled, tries to find the domain of the device,
assuming it's a PCI one, during DMA operations, such as mapping or
unmapping. Since we are splitting the actual PCI device to couple of
children via MFD framework (see drivers/mfd/intel-lpss.c for details),
the DMA device appears to be a platform one, and thus not an actual one
that performs DMA. In a such situation IOMMU can't find or allocate
a proper domain for its operations. As a result, all DMA operations are
failed.

In order to fix this, supply parent of the platform device
to the DMA engine framework and fix filter functions accordingly.

We may rely on the fact that parent is a real PCI device, because no
other configuration is present in the wild.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Acked-by: Mark Brown &lt;broonie@kernel.org&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt; [for tty parts]
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 5ba846b1ee0792f5a596b9b0b86d6e8cdebfab06 ]

Intel IOMMU, when enabled, tries to find the domain of the device,
assuming it's a PCI one, during DMA operations, such as mapping or
unmapping. Since we are splitting the actual PCI device to couple of
children via MFD framework (see drivers/mfd/intel-lpss.c for details),
the DMA device appears to be a platform one, and thus not an actual one
that performs DMA. In a such situation IOMMU can't find or allocate
a proper domain for its operations. As a result, all DMA operations are
failed.

In order to fix this, supply parent of the platform device
to the DMA engine framework and fix filter functions accordingly.

We may rely on the fact that parent is a real PCI device, because no
other configuration is present in the wild.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Acked-by: Mark Brown &lt;broonie@kernel.org&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt; [for tty parts]
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>spi: Fix zero length xfer bug</title>
<updated>2019-06-11T10:24:06+00:00</updated>
<author>
<name>Chris Lesiak</name>
<email>chris.lesiak@licor.com</email>
</author>
<published>2019-03-07T20:39:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0984cb76d2942dd0bf6da77799b931802d8af678'/>
<id>0984cb76d2942dd0bf6da77799b931802d8af678</id>
<content type='text'>
[ Upstream commit 5442dcaa0d90fc376bdfc179a018931a8f43dea4 ]

This fixes a bug for messages containing both zero length and
unidirectional xfers.

The function spi_map_msg will allocate dummy tx and/or rx buffers
for use with unidirectional transfers when the hardware can only do
a bidirectional transfer.  That dummy buffer will be used in place
of a NULL buffer even when the xfer length is 0.

Then in the function __spi_map_msg, if he hardware can dma,
the zero length xfer will have spi_map_buf called on the dummy
buffer.

Eventually, __sg_alloc_table is called and returns -EINVAL
because nents == 0.

This fix prevents the error by not using the dummy buffer when
the xfer length is zero.

Signed-off-by: Chris Lesiak &lt;chris.lesiak@licor.com&gt;
Signed-off-by: Mark Brown &lt;broonie@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 5442dcaa0d90fc376bdfc179a018931a8f43dea4 ]

This fixes a bug for messages containing both zero length and
unidirectional xfers.

The function spi_map_msg will allocate dummy tx and/or rx buffers
for use with unidirectional transfers when the hardware can only do
a bidirectional transfer.  That dummy buffer will be used in place
of a NULL buffer even when the xfer length is 0.

Then in the function __spi_map_msg, if he hardware can dma,
the zero length xfer will have spi_map_buf called on the dummy
buffer.

Eventually, __sg_alloc_table is called and returns -EINVAL
because nents == 0.

This fix prevents the error by not using the dummy buffer when
the xfer length is zero.

Signed-off-by: Chris Lesiak &lt;chris.lesiak@licor.com&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>spi: rspi: Fix sequencer reset during initialization</title>
<updated>2019-06-11T10:24:06+00:00</updated>
<author>
<name>Geert Uytterhoeven</name>
<email>geert+renesas@glider.be</email>
</author>
<published>2019-03-12T18:45:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=854415f37aae8631e7fdf1a2aab70281b4177248'/>
<id>854415f37aae8631e7fdf1a2aab70281b4177248</id>
<content type='text'>
[ Upstream commit 26843bb128590edd7eba1ad7ce22e4b9f1066ce3 ]

While the sequencer is reset after each SPI message since commit
880c6d114fd79a69 ("spi: rspi: Add support for Quad and Dual SPI
Transfers on QSPI"), it was never reset for the first message, thus
relying on reset state or bootloader settings.

Fix this by initializing it explicitly during configuration.

Fixes: 0b2182ddac4b8837 ("spi: add support for Renesas RSPI")
Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Mark Brown &lt;broonie@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 26843bb128590edd7eba1ad7ce22e4b9f1066ce3 ]

While the sequencer is reset after each SPI message since commit
880c6d114fd79a69 ("spi: rspi: Add support for Quad and Dual SPI
Transfers on QSPI"), it was never reset for the first message, thus
relying on reset state or bootloader settings.

Fix this by initializing it explicitly during configuration.

Fixes: 0b2182ddac4b8837 ("spi: add support for Renesas RSPI")
Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>spi : spi-topcliff-pch: Fix to handle empty DMA buffers</title>
<updated>2019-06-11T10:24:05+00:00</updated>
<author>
<name>Aditya Pakki</name>
<email>pakki001@umn.edu</email>
</author>
<published>2019-03-13T16:55:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c927451887c1abdb480ee77f17ba2b20c55285b6'/>
<id>c927451887c1abdb480ee77f17ba2b20c55285b6</id>
<content type='text'>
[ Upstream commit f37d8e67f39e6d3eaf4cc5471e8a3d21209843c6 ]

pch_alloc_dma_buf allocated tx, rx DMA buffers which can fail. Further,
these buffers are used without a check. The patch checks for these
failures and sends the error upstream.

Signed-off-by: Aditya Pakki &lt;pakki001@umn.edu&gt;
Signed-off-by: Mark Brown &lt;broonie@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 f37d8e67f39e6d3eaf4cc5471e8a3d21209843c6 ]

pch_alloc_dma_buf allocated tx, rx DMA buffers which can fail. Further,
these buffers are used without a check. The patch checks for these
failures and sends the error upstream.

Signed-off-by: Aditya Pakki &lt;pakki001@umn.edu&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>spi: tegra114: reset controller on probe</title>
<updated>2019-06-11T10:24:04+00:00</updated>
<author>
<name>Sowjanya Komatineni</name>
<email>skomatineni@nvidia.com</email>
</author>
<published>2019-03-27T05:56:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=557ae685914b5bfdedc61c3d41b188f0f47d3353'/>
<id>557ae685914b5bfdedc61c3d41b188f0f47d3353</id>
<content type='text'>
[ Upstream commit 019194933339b3e9b486639c8cb3692020844d65 ]

Fixes: SPI driver can be built as module so perform SPI controller reset
on probe to make sure it is in valid state before initiating transfer.

Signed-off-by: Sowjanya Komatineni &lt;skomatineni@nvidia.com&gt;
Signed-off-by: Mark Brown &lt;broonie@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 019194933339b3e9b486639c8cb3692020844d65 ]

Fixes: SPI driver can be built as module so perform SPI controller reset
on probe to make sure it is in valid state before initiating transfer.

Signed-off-by: Sowjanya Komatineni &lt;skomatineni@nvidia.com&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>spi: pxa2xx: fix SCR (divisor) calculation</title>
<updated>2019-06-11T10:23:54+00:00</updated>
<author>
<name>Flavio Suligoi</name>
<email>f.suligoi@asem.it</email>
</author>
<published>2019-04-12T07:32:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5e1a879d9ab36ae6bc34737fe40ea6d2c74c71d0'/>
<id>5e1a879d9ab36ae6bc34737fe40ea6d2c74c71d0</id>
<content type='text'>
[ Upstream commit 29f2133717c527f492933b0622a4aafe0b3cbe9e ]

Calculate the divisor for the SCR (Serial Clock Rate), avoiding
that the SSP transmission rate can be greater than the device rate.

When the division between the SSP clock and the device rate generates
a reminder, we have to increment by one the divisor.
In this way the resulting SSP clock will never be greater than the
device SPI max frequency.

For example, with:

 - ssp_clk  = 50 MHz
 - dev freq = 15 MHz

without this patch the SSP clock will be greater than 15 MHz:

 - 25 MHz for PXA25x_SSP and CE4100_SSP
 - 16,56 MHz for the others

Instead, with this patch, we have in both case an SSP clock of 12.5MHz,
so the max rate of the SPI device clock is respected.

Signed-off-by: Flavio Suligoi &lt;f.suligoi@asem.it&gt;
Reviewed-by: Jarkko Nikula &lt;jarkko.nikula@linux.intel.com&gt;
Reviewed-by: Jarkko Nikula &lt;jarkko.nikula@linux.intel.com&gt;
Signed-off-by: Mark Brown &lt;broonie@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 29f2133717c527f492933b0622a4aafe0b3cbe9e ]

Calculate the divisor for the SCR (Serial Clock Rate), avoiding
that the SSP transmission rate can be greater than the device rate.

When the division between the SSP clock and the device rate generates
a reminder, we have to increment by one the divisor.
In this way the resulting SSP clock will never be greater than the
device SPI max frequency.

For example, with:

 - ssp_clk  = 50 MHz
 - dev freq = 15 MHz

without this patch the SSP clock will be greater than 15 MHz:

 - 25 MHz for PXA25x_SSP and CE4100_SSP
 - 16,56 MHz for the others

Instead, with this patch, we have in both case an SSP clock of 12.5MHz,
so the max rate of the SPI device clock is respected.

Signed-off-by: Flavio Suligoi &lt;f.suligoi@asem.it&gt;
Reviewed-by: Jarkko Nikula &lt;jarkko.nikula@linux.intel.com&gt;
Reviewed-by: Jarkko Nikula &lt;jarkko.nikula@linux.intel.com&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>spi: bcm2835: Unbreak the build of esoteric configs</title>
<updated>2019-01-13T09:05:31+00:00</updated>
<author>
<name>Lukas Wunner</name>
<email>lukas@wunner.de</email>
</author>
<published>2018-11-29T14:14:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b76db5ad2f97acfe14993caad0431904eed37dea'/>
<id>b76db5ad2f97acfe14993caad0431904eed37dea</id>
<content type='text'>
commit 29bdedfd9cf40e59456110ca417a8cb672ac9b92 upstream.

Commit e82b0b382845 ("spi: bcm2835: Fix race on DMA termination") broke
the build with COMPILE_TEST=y on arches whose cmpxchg() requires 32-bit
operands (xtensa, older arm ISAs).

Fix by changing the dma_pending flag's type from bool to unsigned int.

Fixes: e82b0b382845 ("spi: bcm2835: Fix race on DMA termination")
Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Cc: Frank Pavlic &lt;f.pavlic@kunbus.de&gt;
Cc: Martin Sperl &lt;kernel@martin.sperl.org&gt;
Cc: Noralf Trønnes &lt;noralf@tronnes.org&gt;
Cc: Sudip Mukherjee &lt;sudipm.mukherjee@gmail.com&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 29bdedfd9cf40e59456110ca417a8cb672ac9b92 upstream.

Commit e82b0b382845 ("spi: bcm2835: Fix race on DMA termination") broke
the build with COMPILE_TEST=y on arches whose cmpxchg() requires 32-bit
operands (xtensa, older arm ISAs).

Fix by changing the dma_pending flag's type from bool to unsigned int.

Fixes: e82b0b382845 ("spi: bcm2835: Fix race on DMA termination")
Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Cc: Frank Pavlic &lt;f.pavlic@kunbus.de&gt;
Cc: Martin Sperl &lt;kernel@martin.sperl.org&gt;
Cc: Noralf Trønnes &lt;noralf@tronnes.org&gt;
Cc: Sudip Mukherjee &lt;sudipm.mukherjee@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>spi: bcm2835: Avoid finishing transfer prematurely in IRQ mode</title>
<updated>2019-01-13T09:05:30+00:00</updated>
<author>
<name>Lukas Wunner</name>
<email>lukas@wunner.de</email>
</author>
<published>2018-11-08T07:06:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dc1715a2b2334a862b2eb41eea2b59ff28ed6a8f'/>
<id>dc1715a2b2334a862b2eb41eea2b59ff28ed6a8f</id>
<content type='text'>
commit 56c1723426d3cfd4723bfbfce531d7b38bae6266 upstream.

The IRQ handler bcm2835_spi_interrupt() first reads as much as possible
from the RX FIFO, then writes as much as possible to the TX FIFO.
Afterwards it decides whether the transfer is finished by checking if
the TX FIFO is empty.

If very few bytes were written to the TX FIFO, they may already have
been transmitted by the time the FIFO's emptiness is checked.  As a
result, the transfer will be declared finished and the chip will be
reset without reading the corresponding received bytes from the RX FIFO.

The odds of this happening increase with a high clock frequency (such
that the TX FIFO drains quickly) and either passing "threadirqs" on the
command line or enabling CONFIG_PREEMPT_RT_BASE (such that the IRQ
handler may be preempted between filling the TX FIFO and checking its
emptiness).

Fix by instead checking whether rx_len has reached zero, which means
that the transfer has been received in full.  This is also more
efficient as it avoids one bus read access per interrupt.  Note that
bcm2835_spi_transfer_one_poll() likewise uses rx_len to determine
whether the transfer has finished.

Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Fixes: e34ff011c70e ("spi: bcm2835: move to the transfer_one driver model")
Cc: stable@vger.kernel.org # v4.1+
Cc: Mathias Duckeck &lt;m.duckeck@kunbus.de&gt;
Cc: Frank Pavlic &lt;f.pavlic@kunbus.de&gt;
Cc: Martin Sperl &lt;kernel@martin.sperl.org&gt;
Cc: Noralf Trønnes &lt;noralf@tronnes.org&gt;
Signed-off-by: Mark Brown &lt;broonie@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 56c1723426d3cfd4723bfbfce531d7b38bae6266 upstream.

The IRQ handler bcm2835_spi_interrupt() first reads as much as possible
from the RX FIFO, then writes as much as possible to the TX FIFO.
Afterwards it decides whether the transfer is finished by checking if
the TX FIFO is empty.

If very few bytes were written to the TX FIFO, they may already have
been transmitted by the time the FIFO's emptiness is checked.  As a
result, the transfer will be declared finished and the chip will be
reset without reading the corresponding received bytes from the RX FIFO.

The odds of this happening increase with a high clock frequency (such
that the TX FIFO drains quickly) and either passing "threadirqs" on the
command line or enabling CONFIG_PREEMPT_RT_BASE (such that the IRQ
handler may be preempted between filling the TX FIFO and checking its
emptiness).

Fix by instead checking whether rx_len has reached zero, which means
that the transfer has been received in full.  This is also more
efficient as it avoids one bus read access per interrupt.  Note that
bcm2835_spi_transfer_one_poll() likewise uses rx_len to determine
whether the transfer has finished.

Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Fixes: e34ff011c70e ("spi: bcm2835: move to the transfer_one driver model")
Cc: stable@vger.kernel.org # v4.1+
Cc: Mathias Duckeck &lt;m.duckeck@kunbus.de&gt;
Cc: Frank Pavlic &lt;f.pavlic@kunbus.de&gt;
Cc: Martin Sperl &lt;kernel@martin.sperl.org&gt;
Cc: Noralf Trønnes &lt;noralf@tronnes.org&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>spi: bcm2835: Fix book-keeping of DMA termination</title>
<updated>2019-01-13T09:05:30+00:00</updated>
<author>
<name>Lukas Wunner</name>
<email>lukas@wunner.de</email>
</author>
<published>2018-11-08T07:06:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4d69a11939573aa2e3295be456e05da70e286596'/>
<id>4d69a11939573aa2e3295be456e05da70e286596</id>
<content type='text'>
commit dbc944115eed48af110646992893dc43321368d8 upstream.

If submission of a DMA TX transfer succeeds but submission of the
corresponding RX transfer does not, the BCM2835 SPI driver terminates
the TX transfer but neglects to reset the dma_pending flag to false.

Thus, if the next transfer uses interrupt mode (because it is shorter
than BCM2835_SPI_DMA_MIN_LENGTH) and runs into a timeout,
dmaengine_terminate_all() will be called both for TX (once more) and
for RX (which was never started in the first place).  Fix it.

Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Fixes: 3ecd37edaa2a ("spi: bcm2835: enable dma modes for transfers meeting certain conditions")
Cc: stable@vger.kernel.org # v4.2+
Cc: Mathias Duckeck &lt;m.duckeck@kunbus.de&gt;
Cc: Frank Pavlic &lt;f.pavlic@kunbus.de&gt;
Cc: Martin Sperl &lt;kernel@martin.sperl.org&gt;
Cc: Noralf Trønnes &lt;noralf@tronnes.org&gt;
Signed-off-by: Mark Brown &lt;broonie@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 dbc944115eed48af110646992893dc43321368d8 upstream.

If submission of a DMA TX transfer succeeds but submission of the
corresponding RX transfer does not, the BCM2835 SPI driver terminates
the TX transfer but neglects to reset the dma_pending flag to false.

Thus, if the next transfer uses interrupt mode (because it is shorter
than BCM2835_SPI_DMA_MIN_LENGTH) and runs into a timeout,
dmaengine_terminate_all() will be called both for TX (once more) and
for RX (which was never started in the first place).  Fix it.

Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Fixes: 3ecd37edaa2a ("spi: bcm2835: enable dma modes for transfers meeting certain conditions")
Cc: stable@vger.kernel.org # v4.2+
Cc: Mathias Duckeck &lt;m.duckeck@kunbus.de&gt;
Cc: Frank Pavlic &lt;f.pavlic@kunbus.de&gt;
Cc: Martin Sperl &lt;kernel@martin.sperl.org&gt;
Cc: Noralf Trønnes &lt;noralf@tronnes.org&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
</feed>
