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Message-ID: <20240510204945.2581944-1-andriy.shevchenko@linux.intel.com>
Date: Fri, 10 May 2024 23:49:45 +0300
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Mark Brown <broonie@...nel.org>,
linux-spi@...r.kernel.org,
linux-kernel@...r.kernel.org
Cc: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Subject: [PATCH v1 1/1] spi: Refactor spi_stop_queue()
The refactoring makes code less verbose and easier to read.
Besides that the binary size is also reduced, which sounds
like a win-win case:
add/remove: 0/1 grow/shrink: 2/2 up/down: 210/-226 (-16)
Function old new delta
spi_destroy_queue 42 156 +114
spi_controller_suspend 101 197 +96
spi_unregister_controller 346 319 -27
spi_register_controller 1834 1794 -40
spi_stop_queue 159 - -159
Total: Before=49230, After=49214, chg -0.03%
Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
drivers/spi/spi.c | 25 ++++++++++---------------
1 file changed, 10 insertions(+), 15 deletions(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 289feccca376..ef0027b9cae5 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2207,11 +2207,8 @@ static int spi_start_queue(struct spi_controller *ctlr)
static int spi_stop_queue(struct spi_controller *ctlr)
{
+ unsigned int limit = 500;
unsigned long flags;
- unsigned limit = 500;
- int ret = 0;
-
- spin_lock_irqsave(&ctlr->queue_lock, flags);
/*
* This is a bit lame, but is optimized for the common execution path.
@@ -2219,20 +2216,18 @@ static int spi_stop_queue(struct spi_controller *ctlr)
* execution path (pump_messages) would be required to call wake_up or
* friends on every SPI message. Do this instead.
*/
- while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
+ do {
+ spin_lock_irqsave(&ctlr->queue_lock, flags);
+ if (list_empty(&ctlr->queue) && !ctlr->busy) {
+ ctlr->running = false;
+ spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+ return 0;
+ }
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
usleep_range(10000, 11000);
- spin_lock_irqsave(&ctlr->queue_lock, flags);
- }
+ } while (--limit);
- if (!list_empty(&ctlr->queue) || ctlr->busy)
- ret = -EBUSY;
- else
- ctlr->running = false;
-
- spin_unlock_irqrestore(&ctlr->queue_lock, flags);
-
- return ret;
+ return -EBUSY;
}
static int spi_destroy_queue(struct spi_controller *ctlr)
--
2.43.0.rc1.1336.g36b5255a03ac
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