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Interfacing (DSI, CSI, I2C, etc.) • Re: Drive dual MIPI DSI panel using Raspberry Pi 5

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The controller for this screen should be R63419, you can download the datasheet here (https://pdfcoffee.com/er63419rev101140628-pdf-free.html).

Sorry I haven't read the datasheet in detail, but according to the table in it, this controller is only capable of up to 1Gbps per channel (\sad).

This controller is capable of single port operation, but I would prefer not to sacrifice refresh rate. I'm not sure if this controller forces the drive signals to be synchronized, but it looks like the left and right parts of the screen are independent.
I have no information on that either. If they are independent, then you have the potential for odd tearing effects as the two halves get updated at different times. It'll depend on your use case as to whether that is a problem.
I'd like to try it out, this driver (https://github.com/raspberrypi/linux/bl ... 01r1sx01.c) doesn't seem to take synchronization into account at all, I didn't find any info on the LQ101R1SX01's controller, but it looks very similar to the LS055R1SX04's interface.
Looking at the device tree binding, I'll agree that there appears to be no synchronisation in the panel definition.
Looking at the one user of it, the primary DSI host controller has a "nvidia,ganged-mode" link to the secondary. Exactly how that works will be down to the host controller implementation.
At last, this may be a silly question, if I start both DSI ports at the same time, and keep both ports at the same frequency, then both DSIs should be roughly synchronized. Why do you say that RP1's two dsi can't be synchronized?
PLLs drift.
Each DSI port has a dedicated PLL to generate whatever link frequency is desired, so even if they are started at exactly the same moment, they'll shift against each other over time.

Thank you very much for your help, I will do some experiments on the panel, see if I can get this to work.

Statistics: Posted by b0wen — Thu Apr 04, 2024 2:05 pm



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