[PATCH 1/6] spi/pl022: only enable RX interrupts when TX is complete
Linus Walleij
linus.walleij at stericsson.com
Wed Nov 9 05:38:50 EST 2011
From: Chris Blair <chris.blair at stericsson.com>
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.
Signed-off-by: Chris Blair <chris.blair at stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
drivers/spi/spi-pl022.c | 14 +++++++++-----
1 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
index 5559b22..b251926 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 +1379,16 @@ 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);
--
1.7.3.2
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