From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan O'Donovan Subject: [PATCH] spi: pxa2xx: use DMA by default if supported Date: Fri, 27 May 2016 19:57:48 +0100 Message-ID: <1464375468-11510-1-git-send-email-dan@emutex.com> Cc: daniel-cYrQPVfZoowdnm+yROfE0A@public.gmane.org, haojian.zhuang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, robert.jarzmik-GANU6spQydw@public.gmane.org, Dan O'Donovan To: linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org Return-path: Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: 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 --- 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); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html