From 470dfd808ac4135f313967f9d3e107b87fc6a0b3 Mon Sep 17 00:00:00 2001 From: Sven Van Asbroeck Date: Mon, 23 Nov 2020 14:15:29 -0500 Subject: [PATCH] lan743x: replace polling loop by wait_event_timeout() The driver's ISR sends a 'software interrupt' event to the probe() thread using the following method: - probe(): write 0 to flag, enable s/w interrupt - probe(): poll on flag, relax using usleep_range() - ISR : write 1 to flag Replace with wake_up() / wait_event_timeout(). Besides being easier to get right, this abstraction has better timing and memory consistency properties. Tested-by: Sven Van Asbroeck # lan7430 Signed-off-by: Sven Van Asbroeck Link: https://lore.kernel.org/r/20201123191529.14908-2-TheSven73@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/microchip/lan743x_main.c | 28 +++++++++---------- drivers/net/ethernet/microchip/lan743x_main.h | 3 +- 2 files changed, 15 insertions(+), 16 deletions(-) diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c index 38ef079bb600..dbd6c3946aa6 100644 --- a/drivers/net/ethernet/microchip/lan743x_main.c +++ b/drivers/net/ethernet/microchip/lan743x_main.c @@ -146,7 +146,8 @@ static void lan743x_intr_software_isr(struct lan743x_adapter *adapter) /* disable the interrupt to prevent repeated re-triggering */ lan743x_csr_write(adapter, INT_EN_CLR, INT_BIT_SW_GP_); - intr->software_isr_flag = 1; + intr->software_isr_flag = true; + wake_up(&intr->software_isr_wq); } static void lan743x_tx_isr(void *context, u32 int_sts, u32 flags) @@ -343,27 +344,22 @@ irq_done: static int lan743x_intr_test_isr(struct lan743x_adapter *adapter) { struct lan743x_intr *intr = &adapter->intr; - int result = -ENODEV; - int timeout = 10; + int ret; - intr->software_isr_flag = 0; + intr->software_isr_flag = false; - /* enable interrupt */ + /* enable and activate test interrupt */ lan743x_csr_write(adapter, INT_EN_SET, INT_BIT_SW_GP_); - - /* activate interrupt here */ lan743x_csr_write(adapter, INT_SET, INT_BIT_SW_GP_); - while ((timeout > 0) && (!(intr->software_isr_flag))) { - usleep_range(1000, 20000); - timeout--; - } - if (intr->software_isr_flag) - result = 0; + ret = wait_event_timeout(intr->software_isr_wq, + intr->software_isr_flag, + msecs_to_jiffies(200)); - /* disable interrupts */ + /* disable test interrupt */ lan743x_csr_write(adapter, INT_EN_CLR, INT_BIT_SW_GP_); - return result; + + return ret > 0 ? 0 : -ENODEV; } static int lan743x_intr_register_isr(struct lan743x_adapter *adapter, @@ -537,6 +533,8 @@ static int lan743x_intr_open(struct lan743x_adapter *adapter) flags |= LAN743X_VECTOR_FLAG_SOURCE_ENABLE_R2C; } + init_waitqueue_head(&intr->software_isr_wq); + ret = lan743x_intr_register_isr(adapter, 0, flags, INT_BIT_ALL_RX_ | INT_BIT_ALL_TX_ | INT_BIT_ALL_OTHER_, diff --git a/drivers/net/ethernet/microchip/lan743x_main.h b/drivers/net/ethernet/microchip/lan743x_main.h index 3a0e70daa88f..404af3f4635e 100644 --- a/drivers/net/ethernet/microchip/lan743x_main.h +++ b/drivers/net/ethernet/microchip/lan743x_main.h @@ -616,7 +616,8 @@ struct lan743x_intr { int number_of_vectors; bool using_vectors; - int software_isr_flag; + bool software_isr_flag; + wait_queue_head_t software_isr_wq; }; #define LAN743X_MAX_FRAME_SIZE (9 * 1024)