korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-13 14:24:11 +08:00
Code Issues Packages Projects Releases Wiki Activity

spi: spidev: use spi_sync instead of spi_async

Browse Source 
This has the benefit that the "optimization" of the framework in regards
to spi_sync will also benefit spidev users directly and allow running
spi transfers without a necessary context-switch to message-pump.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Martin Sperl 2015-04-23 07:56:01 +00:00 committed by Mark Brown
parent c517d838eb
commit 98d6f47958
1 changed files with 10 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
drivers/spi/spidev.c
View File

@ -95,37 +95,25 @@ MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message");
/*-------------------------------------------------------------------------*/
/*
* We can't use the standard synchronous wrappers for file I/O; we
* need to protect against async removal of the underlying spi_device.
*/
static void spidev_complete(void *arg)
{
complete(arg);
}
static ssize_t
spidev_sync(struct spidev_data *spidev, struct spi_message *message)
{
DECLARE_COMPLETION_ONSTACK(done);
int status;
message->complete = spidev_complete;
message->context = &done;
struct spi_device *spi;
spin_lock_irq(&spidev->spi_lock);
if (spidev->spi == NULL)
status = -ESHUTDOWN;
else
status = spi_async(spidev->spi, message);
spi = spidev->spi;
spin_unlock_irq(&spidev->spi_lock);
if (status == 0) {
wait_for_completion(&done);
status = message->status;
if (status == 0)
status = message->actual_length;
}
if (spi == NULL)
status = -ESHUTDOWN;
else
status = spi_sync(spi, message);
if (status == 0)
status = message->actual_length;
return status;
}