From 172289df4004cccf798316b19cc3e6284dbe901f Mon Sep 17 00:00:00 2001 From: Chris Blair Date: Sat, 4 Jun 2011 07:57:47 +0100 Subject: [PATCH] spi/pl022: only enable RX interrupts when TX is complete For interrupt mode transfers, start with only TX interrupts enabled to reduce the overall number of interrupts received. Once TX is complete, enable RX interrupts to complete the transfer. Reviewed-by: Viresh Kumar Signed-off-by: Chris Blair Signed-off-by: Linus Walleij --- drivers/spi/spi-pl022.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c index 5559b2299198..5b7209f9f100 100644 --- a/drivers/spi/spi-pl022.c +++ b/drivers/spi/spi-pl022.c @@ -1244,9 +1244,9 @@ static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id) if ((pl022->tx == pl022->tx_end) && (flag == 0)) { flag = 1; - /* Disable Transmit interrupt */ - writew(readw(SSP_IMSC(pl022->virtbase)) & - (~SSP_IMSC_MASK_TXIM), + /* Disable Transmit interrupt, enable receive interrupt */ + writew((readw(SSP_IMSC(pl022->virtbase)) & + ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase)); } @@ -1379,12 +1379,17 @@ static void pump_transfers(unsigned long data) } err_config_dma: - writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); + /* enable all interrupts except RX */ + writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase)); } static void do_interrupt_dma_transfer(struct pl022 *pl022) { - u32 irqflags = ENABLE_ALL_INTERRUPTS; + /* + * Default is to enable all interrupts except RX - + * this will be enabled once TX is complete + */ + u32 irqflags = ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM; /* Enable target chip */ pl022->cur_chip->cs_control(SSP_CHIP_SELECT);