From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH v2 4/4] spi/dw_spi: improve the interrupt mode with the batch ops Date: Wed, 30 Mar 2011 21:32:45 -0600 Message-ID: <20110331033245.GF19333@ponder.secretlab.ca> References: <1301497795-6924-1-git-send-email-feng.tang@intel.com> <1301497795-6924-5-git-send-email-feng.tang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, alek.du-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, alan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org To: Feng Tang Return-path: Content-Disposition: inline In-Reply-To: <1301497795-6924-5-git-send-email-feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org On Wed, Mar 30, 2011 at 11:09:55PM +0800, Feng Tang wrote: > From: Alek Du > > leverage the performance gain by change in low level > read/write batch operations > > Signed-off-by: Alek Du > Signed-off-by: Feng Tang 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 > ------------------------------------------------------------------------------ Create and publish websites with WebMatrix Use the most popular FREE web apps or write code yourself; WebMatrix provides all the features you need to develop and publish your website. http://p.sf.net/sfu/ms-webmatrix-sf