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authorChris Blair <chris.blair@stericsson.com>2011-06-04 07:57:47 +0100
committerLinus Walleij <linus.walleij@linaro.org>2011-12-01 17:16:07 +0100
commit172289df4004cccf798316b19cc3e6284dbe901f (patch)
treeee82043bd2a819a81416730ba7ac2c882bbb311c /drivers/spi
parentcaca6a03d365883564885f2c1da3e88dcf65d139 (diff)
downloadlinux-172289df4004cccf798316b19cc3e6284dbe901f.tar.bz2
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 <viresh.kumar@st.com> Signed-off-by: Chris Blair <chris.blair@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-pl022.c15
1 files 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);