Messages in this thread | | | Date | Mon, 19 Dec 2022 15:44:14 +0100 | From | Jacopo Mondi <> | Subject | Re: [PATCH v7 1/5] media: i2c: imx334: modify link frequency as for the configureation |
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Hi Shravan
On Mon, Dec 19, 2022 at 11:45:22AM +0530, shravan kumar wrote: > From: Shravan Chippa <shravan.chippa@microchip.com> > > Currently imx334 sensor driver is configured for 1782Mbps/lane for > 3840x2160@60 resolution with reqired reg mode values but if we run the > command "v4l2-ctl --all -d /dev/v4l-subdevX" it is showing incorrect link > frequeny, This is because of the incorrect value of IMX334_LINK_FREQ > witch is 891000000. it should be 1782000000. > > In general with the value of 891000000 link frequency it is not possible > to configure 3840x2160@60 resolution. > > Fixes: 9746b11715c3 ("media: i2c: Add imx334 camera sensor driver") > > Signed-off-by: Shravan Chippa <shravan.chippa@microchip.com> > --- > drivers/media/i2c/imx334.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/media/i2c/imx334.c b/drivers/media/i2c/imx334.c > index 7b0a9086447d..acc9f9f15e47 100644 > --- a/drivers/media/i2c/imx334.c > +++ b/drivers/media/i2c/imx334.c > @@ -49,7 +49,7 @@ > #define IMX334_INCLK_RATE 24000000 > > /* CSI2 HW configuration */ > -#define IMX334_LINK_FREQ 891000000 > +#define IMX334_LINK_FREQ 1782000000
Is this your reasoning ?
width: 3840 hblank: 560 height: 2160 vblank: 2340 bpp: 12 fps: 60 lanes: 4
Total bandwidth: (3840 + 560) * (2160 + 2340) * 60 * 12 = 14.256.000.000 Bandwidth per lane = Total / 4 = 3.564.000.000 mipi clock = Bandwidth_per_lane / 2 = 1.782.000.000
Two questions:
- Should you update the pixel clock as well ? It is currently set to 594000000 while as per the above reasoning it should be doubled too.
- Where is the sensor's clock tree programmed in the driver ? It's kind of weird that the pixel_clock and link_freq in the driver are half of what they theoretically should be...
> #define IMX334_NUM_DATA_LANES 4 > > #define IMX334_REG_MIN 0x00 > -- > 2.34.1 >
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