Hi, Tomasz
Thanks for your review.
On 8/16/19 2:10 PM, Tomasz Figa wrote:
> Hi Bingbu,
>
> On Fri, Aug 16, 2019 at 12:25 PM <bingbu.cao@xxxxxxxxx> wrote:
>>
>> From: Bingbu Cao <bingbu.cao@xxxxxxxxx>
>>
>> Currently, imgu is working on 450MHz for all cases, however
>> in some cases (input frame less than 2.3MP), the imgu
>> did not need work in high frequency.
>> This patch make imgu work on 200MHz if the imgu input
>> frame is less than 2.3MP to save power.
>>
>
> Thanks for the patch! Please see my comments inline.
>
>> Signed-off-by: Bingbu Cao <bingbu.cao@xxxxxxxxx>
>> ---
>> drivers/staging/media/ipu3/ipu3-css.c | 7 ++++---
>> drivers/staging/media/ipu3/ipu3-css.h | 3 ++-
>> drivers/staging/media/ipu3/ipu3-v4l2.c | 6 ++++++
>> drivers/staging/media/ipu3/ipu3.c | 6 ++++--
>> drivers/staging/media/ipu3/ipu3.h | 1 +
>> 5 files changed, 17 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/staging/media/ipu3/ipu3-css.c b/drivers/staging/media/ipu3/ipu3-css.c
>> index fd1ed84c400c..590ed7e182a6 100644
>> --- a/drivers/staging/media/ipu3/ipu3-css.c
>> +++ b/drivers/staging/media/ipu3/ipu3-css.c
>> @@ -210,12 +210,13 @@ static int imgu_hw_wait(void __iomem *base, int reg, u32 mask, u32 cmp)
>>
>> /* Initialize the IPU3 CSS hardware and associated h/w blocks */
>>
>> -int imgu_css_set_powerup(struct device *dev, void __iomem *base)
>> +int imgu_css_set_powerup(struct device *dev, void __iomem *base, bool low_power)
>> {
>> - static const unsigned int freq = 450;
>> + unsigned int freq;
>
> How about making freq the argument to this function rather than
> introducing some artificial boolean?
Let me try to move the check into imgu_powerup().
>
>> u32 pm_ctrl, state, val;
>>
>> - dev_dbg(dev, "%s\n", __func__);
>> + freq = low_power ? 200 : 450;
>> + dev_dbg(dev, "%s with freq %u\n", __func__, freq);
>> /* Clear the CSS busy signal */
>> readl(base + IMGU_REG_GP_BUSY);
>> writel(0, base + IMGU_REG_GP_BUSY);
>> diff --git a/drivers/staging/media/ipu3/ipu3-css.h b/drivers/staging/media/ipu3/ipu3-css.h
>> index 6b8bab27ab1f..882936a9dae9 100644
>> --- a/drivers/staging/media/ipu3/ipu3-css.h
>> +++ b/drivers/staging/media/ipu3/ipu3-css.h
>> @@ -187,7 +187,8 @@ bool imgu_css_is_streaming(struct imgu_css *css);
>> bool imgu_css_pipe_queue_empty(struct imgu_css *css, unsigned int pipe);
>>
>> /******************* css hw *******************/
>> -int imgu_css_set_powerup(struct device *dev, void __iomem *base);
>> +int imgu_css_set_powerup(struct device *dev, void __iomem *base,
>> + bool low_power);
>> void imgu_css_set_powerdown(struct device *dev, void __iomem *base);
>> int imgu_css_irq_ack(struct imgu_css *css);
>>
>> diff --git a/drivers/staging/media/ipu3/ipu3-v4l2.c b/drivers/staging/media/ipu3/ipu3-v4l2.c
>> index 3c7ad1eed434..dcc2a0476e49 100644
>> --- a/drivers/staging/media/ipu3/ipu3-v4l2.c
>> +++ b/drivers/staging/media/ipu3/ipu3-v4l2.c
>> @@ -182,6 +182,12 @@ static int imgu_subdev_set_fmt(struct v4l2_subdev *sd,
>> fmt->format.height = clamp(fmt->format.height,
>> IPU3_INPUT_MIN_HEIGHT,
>> IPU3_INPUT_MAX_HEIGHT);
>> +
>> + /* input less than 2.3MP, ask imgu to work with low freq */
>> + if ((fmt->format.width * fmt->format.height) < (2048 * 1152))
>
> Why 2048 * 1152 specifically if we just care about the number of
> pixels? Also it's slightly more than 2.3Mpix (2.359296 Mpix) making
> the comment inaccurate.
2048 *1152 is the smallest common 16:9/4:3 resolution that larger than
1080p, we try to use this resolution as the start point to make imgu
work on high frequency.
>
>> + imgu->low_power = true;
>> + else
>> + imgu->low_power = false;
>
> There should be no need to store this, as we should have access to the
> exact format when we start streaming. Could you move the check there?
>
> Also, we have 2 pipes. How do they play together?
We want to guarantee 2 pipes can always work on each frequency, there is
no precise calculation which can be used to make more finer granularity.
>
> Best regards,
> Tomasz
>
