Draft PR for exploring fixes to camera sync issues #6863
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To avoid lost frame start in a subsequent session, avoid setting the number of lanes back to 1 or putting CSI-2 Host into reset. It's not clear if this is a watertight fix -- what if the camera itself produced a truncated or garbled packet, or continued to send until the next start? -- but it does seem to fix the issue. Signed-off-by: Nick Hollinghurst <nick.hollinghurst@raspberrypi.com>
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| @@ -112,6 +112,9 @@ MODULE_PARM_DESC(trigger_mode, "Set vsync trigger mode: 1=source, 2=sink"); | |||
| #define IMX477_REG_XVS_IO_CTRL 0x3040 | |||
| #define IMX477_REG_EXTOUT_EN 0x4b81 | |||
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| /* Temperature sensor */ | |||
| #define IMX477_REG_TEMP_SEN_CTL 0x0138 | |||
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As you've defined this, it'd be nice to use that define in mode_common_regs so all instances of 0x0138 are by name.
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My comments are largely in regard to the imx477 change. I know very little of the CFE DPHY side. |
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On IMX477 it appears that the on-chip temperature sensor causes XVS (external sync out) to pulse every ~2ms when not streaming. So now we do a little dance: Temperature sensor is enabled during common register setup, giving it time to warm up (almost literally; otherwise the first frame's reading might be 0C), disabled before enabling sync out, then enabled again once the camera is streaming. We already took care to disable XVS output in stop_streaming() (though previously it wasn't understood why this was needed). Signed-off-by: Nick Hollinghurst <nick.hollinghurst@raspberrypi.com>
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Two issues currently, one is #5821 and is specific to Raspberry Pi 5.
There is also an IMX477 issue, where there are very rarely extra XVS pulses, causing receiving cameras to record a blank frame.