[v2,1/2] spi: Add call to spi_slave_abort() function when spidev driver is released
diff mbox series

Message ID 20190925091143.15468-2-lukma@denx.de
State Accepted
Commit 9f918a728cf86b2757b6a7025e1f46824bfe3155
Headers show
Series
  • spi: Fix problem with interrupted slave transmission
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Commit Message

Lukasz Majewski Sept. 25, 2019, 9:11 a.m. UTC
This change is necessary for spidev devices (e.g. /dev/spidev3.0) working
in the slave mode (like NXP's dspi driver for Vybrid SoC).

When SPI HW works in this mode - the master is responsible for providing
CS and CLK signals. However, when some fault happens - like for example
distortion on SPI lines - the SPI Linux driver needs a chance to recover
from this abnormal situation and prepare itself for next (correct)
transmission.

This change doesn't pose any threat on drivers working in master mode as
spi_slave_abort() function checks if SPI slave mode is supported.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
Link: https://lore.kernel.org/r/20190924110547.14770-2-lukma@denx.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Reported-by: kbuild test robot <lkp@intel.com>

---
Changes for v2:
- Add #ifdef CONFIG_SPI_SLAVE to not compile in spi_slave_abort() on systems
  which are only using master mode.
  (The spi_slave_abort() is 'protected' by this Kconfig define in drivers/spi.c
  file).
  This error was spotted by kbuild test robot from Intel.
---
 drivers/spi/spidev.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Mark Brown Sept. 25, 2019, 4:45 p.m. UTC | #1
On Wed, Sep 25, 2019 at 11:11:42AM +0200, Lukasz Majewski wrote:
> This change is necessary for spidev devices (e.g. /dev/spidev3.0) working
> in the slave mode (like NXP's dspi driver for Vybrid SoC).

Please do not submit new versions of already applied patches, please
submit incremental updates to the existing code.  Modifying existing
commits creates problems for other users building on top of those
commits so it's best practice to only change pubished git commits if
absolutely essential.

That said I'll handle this this one time.
Lukasz Majewski Sept. 25, 2019, 7:57 p.m. UTC | #2
Hi Mark,

> On Wed, Sep 25, 2019 at 11:11:42AM +0200, Lukasz Majewski wrote:
> > This change is necessary for spidev devices (e.g. /dev/spidev3.0)
> > working in the slave mode (like NXP's dspi driver for Vybrid SoC).  
> 
> Please do not submit new versions of already applied patches, please
> submit incremental updates to the existing code.  Modifying existing
> commits creates problems for other users building on top of those
> commits so it's best practice to only change pubished git commits if
> absolutely essential.
> 
> That said I'll handle this this one time.

Thanks for help (and patience).


Best regards,

Lukasz Majewski

--

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Patch
diff mbox series

diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index 255786f2e844..3ea9d8a3e6e8 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -627,6 +627,9 @@  static int spidev_release(struct inode *inode, struct file *filp)
 		if (dofree)
 			kfree(spidev);
 	}
+#ifdef CONFIG_SPI_SLAVE
+	spi_slave_abort(spidev->spi);
+#endif
 	mutex_unlock(&device_list_lock);
 
 	return 0;