On Wed, Mar 30, 2011 at 11:09:55PM +0800, Feng Tang wrote:
> From: Alek Du <[email protected]>
>
> leverage the performance gain by change in low level
> read/write batch operations
>
> Signed-off-by: Alek Du <[email protected]>
> Signed-off-by: Feng Tang <[email protected]>
Applied, thanks.
g.
> ---
> drivers/spi/dw_spi.c | 63 ++++++++++++-------------------------------------
> 1 files changed, 16 insertions(+), 47 deletions(-)
>
> diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c
> index 7a2a722..855ac4a 100644
> --- a/drivers/spi/dw_spi.c
> +++ b/drivers/spi/dw_spi.c
> @@ -190,21 +190,7 @@ static inline u32 rx_max(struct dw_spi *dws)
> return min(rx_left, (u32)dw_readw(dws, rxflr));
> }
>
> -
> -static void wait_till_not_busy(struct dw_spi *dws)
> -{
> - unsigned long end = jiffies + 1 + usecs_to_jiffies(5000);
> -
> - while (time_before(jiffies, end)) {
> - if (!(dw_readw(dws, sr) & SR_BUSY))
> - return;
> - cpu_relax();
> - }
> - dev_err(&dws->master->dev,
> - "DW SPI: Status keeps busy for 5000us after a read/write!\n");
> -}
> -
> -static int dw_writer(struct dw_spi *dws)
> +static void dw_writer(struct dw_spi *dws)
> {
> u32 max = tx_max(dws);
> u16 txw = 0;
> @@ -220,11 +206,9 @@ static int dw_writer(struct dw_spi *dws)
> dw_writew(dws, dr, txw);
> dws->tx += dws->n_bytes;
> }
> -
> - return 1;
> }
>
> -static int dw_reader(struct dw_spi *dws)
> +static void dw_reader(struct dw_spi *dws)
> {
> u32 max = rx_max(dws);
> u16 rxw;
> @@ -240,8 +224,6 @@ static int dw_reader(struct dw_spi *dws)
> }
> dws->rx += dws->n_bytes;
> }
> -
> - return dws->rx == dws->rx_end;
> }
>
> static void *next_transfer(struct dw_spi *dws)
> @@ -340,35 +322,28 @@ EXPORT_SYMBOL_GPL(dw_spi_xfer_done);
>
> static irqreturn_t interrupt_transfer(struct dw_spi *dws)
> {
> - u16 irq_status, irq_mask = 0x3f;
> - u32 int_level = dws->fifo_len / 2;
> - u32 left;
> + u16 irq_status = dw_readw(dws, isr);
>
> - irq_status = dw_readw(dws, isr) & irq_mask;
> /* Error handling */
> if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) {
> dw_readw(dws, txoicr);
> dw_readw(dws, rxoicr);
> dw_readw(dws, rxuicr);
> - int_error_stop(dws, "interrupt_transfer: fifo overrun");
> + int_error_stop(dws, "interrupt_transfer: fifo
> overrun/underrun");
> return IRQ_HANDLED;
> }
>
> + dw_reader(dws);
> + if (dws->rx_end == dws->rx) {
> + spi_mask_intr(dws, SPI_INT_TXEI);
> + dw_spi_xfer_done(dws);
> + return IRQ_HANDLED;
> + }
> if (irq_status & SPI_INT_TXEI) {
> spi_mask_intr(dws, SPI_INT_TXEI);
> -
> - left = (dws->tx_end - dws->tx) / dws->n_bytes;
> - left = (left > int_level) ? int_level : left;
> -
> - while (left--)
> - dw_writer(dws);
> - dw_reader(dws);
> -
> - /* Re-enable the IRQ if there is still data left to tx */
> - if (dws->tx_end > dws->tx)
> - spi_umask_intr(dws, SPI_INT_TXEI);
> - else
> - dw_spi_xfer_done(dws);
> + dw_writer(dws);
> + /* Enable TX irq always, it will be disabled when RX finished */
> + spi_umask_intr(dws, SPI_INT_TXEI);
> }
>
> return IRQ_HANDLED;
> @@ -377,15 +352,13 @@ static irqreturn_t interrupt_transfer(struct dw_spi
> *dws)
> static irqreturn_t dw_spi_irq(int irq, void *dev_id)
> {
> struct dw_spi *dws = dev_id;
> - u16 irq_status, irq_mask = 0x3f;
> + u16 irq_status = dw_readw(dws, isr) & 0x3f;
>
> - irq_status = dw_readw(dws, isr) & irq_mask;
> if (!irq_status)
> return IRQ_NONE;
>
> if (!dws->cur_msg) {
> spi_mask_intr(dws, SPI_INT_TXEI);
> - /* Never fail */
> return IRQ_HANDLED;
> }
>
> @@ -492,12 +465,8 @@ static void pump_transfers(unsigned long data)
>
> switch (bits) {
> case 8:
> - dws->n_bytes = 1;
> - dws->dma_width = 1;
> - break;
> case 16:
> - dws->n_bytes = 2;
> - dws->dma_width = 2;
> + dws->n_bytes = dws->dma_width = bits >> 3;
> break;
> default:
> printk(KERN_ERR "MRST SPI0: unsupported bits:"
> @@ -541,7 +510,7 @@ static void pump_transfers(unsigned long data)
> txint_level = dws->fifo_len / 2;
> txint_level = (templen > txint_level) ? txint_level : templen;
>
> - imask |= SPI_INT_TXEI;
> + imask |= SPI_INT_TXEI | SPI_INT_TXOI | SPI_INT_RXUI |
> SPI_INT_RXOI;
> dws->transfer_handler = interrupt_transfer;
> }
>
> --
> 1.7.0.4
>
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