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spi/xilinx: Do not inhibit transmission in polling mode 

When no irq is used, there is no need to inhibit the transmission for
every transaction. This inhibition was implemented to avoid a race
condition with the irq handler.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Ricardo Ribalda Delgado 2015-01-28 13:23:45 +01:00 committed by Mark Brown
parent 5fe11cc09c
commit d9f5881242
1 changed files with 15 additions and 10 deletions
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25
drivers/spi/spi-xilinx.c
View File

@ -163,6 +163,7 @@ static void xspi_rx32(struct xilinx_spi *xspi)
static void xspi_init_hw(struct xilinx_spi *xspi)
{
void __iomem *regs_base = xspi->regs;
u32 inhibit;
/* Reset the SPI device */
xspi->write_fn(XIPIF_V123B_RESET_MASK,
@ -173,16 +174,19 @@ static void xspi_init_hw(struct xilinx_spi *xspi)
xspi->write_fn(XSPI_INTR_TX_EMPTY,
regs_base + XIPIF_V123B_IIER_OFFSET);
/* Enable the global IPIF interrupt */
if (xspi->irq >= 0)
if (xspi->irq >= 0) {
xspi->write_fn(XIPIF_V123B_GINTR_ENABLE,
regs_base + XIPIF_V123B_DGIER_OFFSET);
else
inhibit = XSPI_CR_TRANS_INHIBIT;
} else {
xspi->write_fn(0, regs_base + XIPIF_V123B_DGIER_OFFSET);
inhibit = 0;
}
/* Deselect the slave on the SPI bus */
xspi->write_fn(0xffff, regs_base + XSPI_SSR_OFFSET);
/* Disable the transmitter, enable Manual Slave Select Assertion,
* put SPI controller into master mode, and enable it */
xspi->write_fn(XSPI_CR_TRANS_INHIBIT | XSPI_CR_MANUAL_SSELECT |
xspi->write_fn(inhibit | XSPI_CR_MANUAL_SSELECT |
XSPI_CR_MASTER_MODE | XSPI_CR_ENABLE | XSPI_CR_TXFIFO_RESET |
XSPI_CR_RXFIFO_RESET, regs_base + XSPI_CR_OFFSET);
}
@ -252,7 +256,7 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
reinit_completion(&xspi->done);
while (xspi->remaining_bytes) {
u16 cr;
u16 cr = 0;
int n_words;
n_words = (xspi->remaining_bytes * 8) / xspi->bits_per_word;
@ -263,13 +267,13 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
/* Start the transfer by not inhibiting the transmitter any
* longer
*/
cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) &
~XSPI_CR_TRANS_INHIBIT;
xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);
if (xspi->irq >= 0)
if (xspi->irq >= 0) {
cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) &
~XSPI_CR_TRANS_INHIBIT;
xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);
wait_for_completion(&xspi->done);
else
} else
while (!(xspi->read_fn(xspi->regs + XSPI_SR_OFFSET) &
XSPI_SR_TX_EMPTY_MASK))
;
@ -279,7 +283,8 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
* transmitter while the Isr refills the transmit register/FIFO,
* or make sure it is stopped if we're done.
*/
xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT,
if (xspi->irq >= 0)
xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT,
xspi->regs + XSPI_CR_OFFSET);
/* Read out all the data from the Rx FIFO */