| Message ID | 1411060140-2801-5-git-send-email-andriy.shevchenko@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Sep 18, 2014 at 08:08:54PM +0300, Andy Shevchenko wrote: > Though intel-mid-dma does not follow a new DMA workflow let's prepare SPI DW > driver for that. I don't understand what this change is supposed to do - what is "a new DMA workflow"?
On Wed, 2014-09-24 at 09:44 +0100, Mark Brown wrote: > On Thu, Sep 18, 2014 at 08:08:54PM +0300, Andy Shevchenko wrote: > > Though intel-mid-dma does not follow a new DMA workflow let's prepare SPI DW > > driver for that. > > I don't understand what this change is supposed to do - what is "a new > DMA workflow"? The client is obliged to call dma_async_issue_pending() which starts the actual transfers. Old DMA drivers do not follow this, since requirement was introduced in 2011 IIRC. Current DMA driver for spi-dw doesn't follow this, but dw_dmac does.
On Wed, Sep 24, 2014 at 01:35:38PM +0300, Andy Shevchenko wrote: > On Wed, 2014-09-24 at 09:44 +0100, Mark Brown wrote: > > On Thu, Sep 18, 2014 at 08:08:54PM +0300, Andy Shevchenko wrote: > > > Though intel-mid-dma does not follow a new DMA workflow let's prepare SPI DW > > > driver for that. > > I don't understand what this change is supposed to do - what is "a new > > DMA workflow"? > The client is obliged to call dma_async_issue_pending() which starts the > actual transfers. Old DMA drivers do not follow this, since requirement > was introduced in 2011 IIRC. > Current DMA driver for spi-dw doesn't follow this, but dw_dmac does. So be specific about it missing the call so someone reading the changelog can understand what this is supposed to do.
On Wed, 2014-09-24 at 12:08 +0100, Mark Brown wrote: > On Wed, Sep 24, 2014 at 01:35:38PM +0300, Andy Shevchenko wrote: > > On Wed, 2014-09-24 at 09:44 +0100, Mark Brown wrote: > > > On Thu, Sep 18, 2014 at 08:08:54PM +0300, Andy Shevchenko wrote: > > > > Though intel-mid-dma does not follow a new DMA workflow let's prepare SPI DW > > > > driver for that. > > > > I don't understand what this change is supposed to do - what is "a new > > > DMA workflow"? > > > The client is obliged to call dma_async_issue_pending() which starts the > > actual transfers. Old DMA drivers do not follow this, since requirement > > was introduced in 2011 IIRC. > > > Current DMA driver for spi-dw doesn't follow this, but dw_dmac does. > > So be specific about it missing the call so someone reading the > changelog can understand what this is supposed to do. Will do.
diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c index 27150c7..a62413d 100644 --- a/drivers/spi/spi-dw-mid.c +++ b/drivers/spi/spi-dw-mid.c @@ -152,7 +152,7 @@ static int mid_spi_dma_transfer(struct dw_spi *dws, int cs_change) &dws->tx_sgl, 1, DMA_MEM_TO_DEV, - DMA_PREP_INTERRUPT); + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); txdesc->callback = dw_spi_dma_done; txdesc->callback_param = dws; @@ -175,13 +175,17 @@ static int mid_spi_dma_transfer(struct dw_spi *dws, int cs_change) &dws->rx_sgl, 1, DMA_DEV_TO_MEM, - DMA_PREP_INTERRUPT); + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); rxdesc->callback = dw_spi_dma_done; rxdesc->callback_param = dws; /* rx must be started before tx due to spi instinct */ rxdesc->tx_submit(rxdesc); txdesc->tx_submit(txdesc); + + dma_async_issue_pending(rxchan); + dma_async_issue_pending(txchan); + return 0; }
Though intel-mid-dma does not follow a new DMA workflow let's prepare SPI DW driver for that. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- drivers/spi/spi-dw-mid.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)