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[3/8] spi: sirf: enable RX_IO_DMA_INT interrupt

Message ID 1409648468-5436-4-git-send-email-Barry.Song@csr.com (mailing list archive)
State Accepted
Commit f2a08b404691ef3e7be6ce81c185335cfc68b6db
Headers show

Commit Message

Barry Song Sept. 2, 2014, 9:01 a.m. UTC 
From: Qipan Li <Qipan.Li@csr.com>

in spi interrupt handler, we need check RX_IO_DMA status to ensure
rx fifo have received the specify count data.

if not set, the while statement in spi isr function will keep loop,
at last, make the kernel hang.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
---
 drivers/spi/spi-sirf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Mark Brown Sept. 4, 2014, 7:27 p.m. UTC | #1 
On Tue, Sep 02, 2014 at 05:01:03PM +0800, Barry Song wrote:

> in spi interrupt handler, we need check RX_IO_DMA status to ensure
> rx fifo have received the specify count data.

> if not set, the while statement in spi isr function will keep loop,
> at last, make the kernel hang.

This changelog says we must check the status in the interrupt handler
but...

>  		writel(SIRFSOC_SPI_TXFIFO_EMPTY_INT_EN |
>  			SIRFSOC_SPI_TX_UFLOW_INT_EN |
> -			SIRFSOC_SPI_RX_OFLOW_INT_EN,
> +			SIRFSOC_SPI_RX_OFLOW_INT_EN |
> +			SIRFSOC_SPI_RX_IO_DMA_INT_EN,
>  			sspi->base + SIRFSOC_SPI_INT_EN);
>  		writel(SIRFSOC_SPI_RX_EN | SIRFSOC_SPI_TX_EN,
>  			sspi->base + SIRFSOC_SPI_TX_RX_EN);

...the change is actually just unmasking a bit in the interrupt mask
register and doesn't add anything to the interrupt handler?  Looking at
the code it seems that the actual issue is that the mask register causes
the interrupt handler not to see the mask bit since the mask not only
disables the interrupt but also causes the bit not to report in the
status register. 

That makes sense so I've applied this but please try to be clear about
things like this, it's hard to review code where the changelog doesn't
clearly match the code.
diff mbox

Patch

diff --git a/drivers/spi/spi-sirf.c b/drivers/spi/spi-sirf.c
index a21e423..7789385 100644
--- a/drivers/spi/spi-sirf.c
+++ b/drivers/spi/spi-sirf.c
@@ -437,7 +437,8 @@  static void spi_sirfsoc_pio_transfer(struct spi_device *spi,
 			sspi->tx_word(sspi);
 		writel(SIRFSOC_SPI_TXFIFO_EMPTY_INT_EN |
 			SIRFSOC_SPI_TX_UFLOW_INT_EN |
-			SIRFSOC_SPI_RX_OFLOW_INT_EN,
+			SIRFSOC_SPI_RX_OFLOW_INT_EN |
+			SIRFSOC_SPI_RX_IO_DMA_INT_EN,
 			sspi->base + SIRFSOC_SPI_INT_EN);
 		writel(SIRFSOC_SPI_RX_EN | SIRFSOC_SPI_TX_EN,
 			sspi->base + SIRFSOC_SPI_TX_RX_EN);