diff options
author | David Lechner <dlechner@baylibre.com> | 2024-01-26 02:47:31 +0300 |
---|---|---|
committer | Mark Brown <broonie@kernel.org> | 2024-01-26 17:35:43 +0300 |
commit | 0da9a5794cfda615668eaefde811e8ef378134fe (patch) | |
tree | dd9ae1bcf297458dadcdfe6e795038a09d8edf47 /drivers | |
parent | a6fc5c5b35f688480167a7a7947ddd91c07e72c8 (diff) | |
download | linux-0da9a5794cfda615668eaefde811e8ef378134fe.tar.xz |
spi: avoid double validation in __spi_sync()
The __spi_sync() function calls __spi_validate() early in the function.
Later, it can call spi_async_locked() which calls __spi_validate()
again. __spi_validate() is an expensive function, so we can improve
performance measurably by avoiding calling it twice.
Instead of calling spi_async_locked(), we can call __spi_async() with
the spin lock held.
spi_async_locked() is removed since there are no more callers.
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://msgid.link/r/20240125234732.3530278-2-dlechner@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/spi/spi.c | 58 |
1 files changed, 6 insertions, 52 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 7a70ef47cdf6..6610aeced765 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -4278,57 +4278,6 @@ int spi_async(struct spi_device *spi, struct spi_message *message) } EXPORT_SYMBOL_GPL(spi_async); -/** - * spi_async_locked - version of spi_async with exclusive bus usage - * @spi: device with which data will be exchanged - * @message: describes the data transfers, including completion callback - * Context: any (IRQs may be blocked, etc) - * - * This call may be used in_irq and other contexts which can't sleep, - * as well as from task contexts which can sleep. - * - * The completion callback is invoked in a context which can't sleep. - * Before that invocation, the value of message->status is undefined. - * When the callback is issued, message->status holds either zero (to - * indicate complete success) or a negative error code. After that - * callback returns, the driver which issued the transfer request may - * deallocate the associated memory; it's no longer in use by any SPI - * core or controller driver code. - * - * Note that although all messages to a spi_device are handled in - * FIFO order, messages may go to different devices in other orders. - * Some device might be higher priority, or have various "hard" access - * time requirements, for example. - * - * On detection of any fault during the transfer, processing of - * the entire message is aborted, and the device is deselected. - * Until returning from the associated message completion callback, - * no other spi_message queued to that device will be processed. - * (This rule applies equally to all the synchronous transfer calls, - * which are wrappers around this core asynchronous primitive.) - * - * Return: zero on success, else a negative error code. - */ -static int spi_async_locked(struct spi_device *spi, struct spi_message *message) -{ - struct spi_controller *ctlr = spi->controller; - int ret; - unsigned long flags; - - ret = __spi_validate(spi, message); - if (ret != 0) - return ret; - - spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); - - ret = __spi_async(spi, message); - - spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); - - return ret; - -} - static void __spi_transfer_message_noqueue(struct spi_controller *ctlr, struct spi_message *msg) { bool was_busy; @@ -4376,6 +4325,7 @@ static void spi_complete(void *arg) static int __spi_sync(struct spi_device *spi, struct spi_message *message) { DECLARE_COMPLETION_ONSTACK(done); + unsigned long flags; int status; struct spi_controller *ctlr = spi->controller; @@ -4419,7 +4369,11 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message) */ message->complete = spi_complete; message->context = &done; - status = spi_async_locked(spi, message); + + spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); + status = __spi_async(spi, message); + spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); + if (status == 0) { wait_for_completion(&done); status = message->status; |