| Message ID | 1464375468-11510-1-git-send-email-dan@emutex.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | c64e1265ae8516c0282b45e099ac5fbdb8486c4c |
| Headers | show |
Dan O'Donovan <dan@emutex.com> writes: Let me add Jarkko and Mika to the review, they were active in the driver's DMA area lately. Cheers. -- Robert [1] Dan's patch > Currently, even if the PXA2xx SPI master supports DMA, it won't be > enabled unless (i) the slave device is enumerated through ACPI, or > (ii) the slave device is registered with board-specific > controller_data specified. Even then, there isn't a field in the > controller_data that explicitly enables dma - it just gets enabled > if the master supports it and controller_data is non-NULL. > > This means that drivers which register SPI devices on a bus without > awareness of this controller cannot avail of DMA performance gains. > > This patch allows DMA transfers to be used if supported. > > Signed-off-by: Dan O'Donovan <dan@emutex.com> > --- > drivers/spi/spi-pxa2xx.c | 10 +--------- > 1 file changed, 1 insertion(+), 9 deletions(-) > > diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c > index fe07c05..27e0307 100644 > --- a/drivers/spi/spi-pxa2xx.c > +++ b/drivers/spi/spi-pxa2xx.c > @@ -1240,7 +1240,7 @@ static int setup(struct spi_device *spi) > chip->frm = spi->chip_select; > } else > chip->gpio_cs = -1; > - chip->enable_dma = 0; > + chip->enable_dma = drv_data->master_info->enable_dma; > chip->timeout = TIMOUT_DFLT; > } > > @@ -1259,17 +1259,9 @@ static int setup(struct spi_device *spi) > tx_hi_thres = chip_info->tx_hi_threshold; > if (chip_info->rx_threshold) > rx_thres = chip_info->rx_threshold; > - chip->enable_dma = drv_data->master_info->enable_dma; > chip->dma_threshold = 0; > if (chip_info->enable_loopback) > chip->cr1 = SSCR1_LBM; > - } else if (ACPI_HANDLE(&spi->dev)) { > - /* > - * Slave devices enumerated from ACPI namespace don't > - * usually have chip_info but we still might want to use > - * DMA with them. > - */ > - chip->enable_dma = drv_data->master_info->enable_dma; > } > > chip->lpss_rx_threshold = SSIRF_RxThresh(rx_thres); -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/27/2016 10:21 PM, Robert Jarzmik wrote: > Dan O'Donovan <dan@emutex.com> writes: > > Let me add Jarkko and Mika to the review, they were active in the driver's DMA > area lately. > > Cheers. > > -- > Robert > > [1] Dan's patch >> Currently, even if the PXA2xx SPI master supports DMA, it won't be >> enabled unless (i) the slave device is enumerated through ACPI, or >> (ii) the slave device is registered with board-specific >> controller_data specified. Even then, there isn't a field in the >> controller_data that explicitly enables dma - it just gets enabled >> if the master supports it and controller_data is non-NULL. >> >> This means that drivers which register SPI devices on a bus without >> awareness of this controller cannot avail of DMA performance gains. >> >> This patch allows DMA transfers to be used if supported. >> Makes sense to me. I've noticed this too but haven't actually touched it if some legacy stuff depends on it. Given that legacy PXA DMA support has been dropped it's probably time to get this cleanup too. Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index fe07c05..27e0307 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -1240,7 +1240,7 @@ static int setup(struct spi_device *spi) chip->frm = spi->chip_select; } else chip->gpio_cs = -1; - chip->enable_dma = 0; + chip->enable_dma = drv_data->master_info->enable_dma; chip->timeout = TIMOUT_DFLT; } @@ -1259,17 +1259,9 @@ static int setup(struct spi_device *spi) tx_hi_thres = chip_info->tx_hi_threshold; if (chip_info->rx_threshold) rx_thres = chip_info->rx_threshold; - chip->enable_dma = drv_data->master_info->enable_dma; chip->dma_threshold = 0; if (chip_info->enable_loopback) chip->cr1 = SSCR1_LBM; - } else if (ACPI_HANDLE(&spi->dev)) { - /* - * Slave devices enumerated from ACPI namespace don't - * usually have chip_info but we still might want to use - * DMA with them. - */ - chip->enable_dma = drv_data->master_info->enable_dma; } chip->lpss_rx_threshold = SSIRF_RxThresh(rx_thres);
Currently, even if the PXA2xx SPI master supports DMA, it won't be enabled unless (i) the slave device is enumerated through ACPI, or (ii) the slave device is registered with board-specific controller_data specified. Even then, there isn't a field in the controller_data that explicitly enables dma - it just gets enabled if the master supports it and controller_data is non-NULL. This means that drivers which register SPI devices on a bus without awareness of this controller cannot avail of DMA performance gains. This patch allows DMA transfers to be used if supported. Signed-off-by: Dan O'Donovan <dan@emutex.com> --- drivers/spi/spi-pxa2xx.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-)