[PATCH] media: atmel-isi: increase the burst length to improve the performance
From: Guennadi Liakhovetski <hidden>
Date: 2014-11-25 22:21:53
Also in:
linux-media
Hi Josh, On Tue, 25 Nov 2014, Josh Wu wrote:
The burst length could be BEATS_4/8/16. Before this patch, isi use default value BEATS_4. To imporve the performance we could set it to BEATS_16. Otherwise sometime it would cause the ISI overflow error.
Without looking at datasheets - what does this bit do? Change the transfer length? What happens then if the data amount isn't a multiple of the transfer size? Thanks Guennadi
quoted hunk ↗ jump to hunk
Reported-by: Bo Shen <redacted> Signed-off-by: Josh Wu <redacted> --- drivers/media/platform/soc_camera/atmel-isi.c | 2 ++ include/media/atmel-isi.h | 4 ++++ 2 files changed, 6 insertions(+)diff --git a/drivers/media/platform/soc_camera/atmel-isi.c b/drivers/media/platform/soc_camera/atmel-isi.c index ee5650f..fda587b 100644 --- a/drivers/media/platform/soc_camera/atmel-isi.c +++ b/drivers/media/platform/soc_camera/atmel-isi.c@@ -839,6 +839,8 @@ static int isi_camera_set_bus_param(struct soc_camera_device *icd) if (isi->pdata.full_mode) cfg1 |= ISI_CFG1_FULL_MODE; + cfg1 |= ISI_CFG1_THMASK_BEATS_16; + isi_writel(isi, ISI_CTRL, ISI_CTRL_DIS); isi_writel(isi, ISI_CFG1, cfg1);diff --git a/include/media/atmel-isi.h b/include/media/atmel-isi.h index c2e5703..6008b09 100644 --- a/include/media/atmel-isi.h +++ b/include/media/atmel-isi.h@@ -59,6 +59,10 @@ #define ISI_CFG1_FRATE_DIV_MASK (7 << 8) #define ISI_CFG1_DISCR (1 << 11) #define ISI_CFG1_FULL_MODE (1 << 12) +/* Definition for THMASK(ISI_V2) */ +#define ISI_CFG1_THMASK_BEATS_4 (0 << 13) +#define ISI_CFG1_THMASK_BEATS_8 (1 << 13) +#define ISI_CFG1_THMASK_BEATS_16 (2 << 13) /* Bitfields in CFG2 */ #define ISI_CFG2_GRAYSCALE (1 << 13)-- 1.9.1