[PATCH v8 01/14] drm: exynos: dsi: Fix MIPI_DSI*_NO_* mode flags

Marek Vasut marex at denx.de
Sat Nov 12 16:29:25 PST 2022


On 11/11/22 13:12, Nicolas Boichat wrote:

[...]

>>> BTW, are you sure DSIM_HSE_MODE is correct now?
>>
>> Yes, we have tested in imx8m platforms as well. Sébastien Szymanski
>> initially observed this issue on the imx8m platform.
> 
> I'll repeat, are you sure about HSE specifically? You invert the
> polarity for HBP, HFP, and HSA, which makes sense given your patch
> 02/14.
> 
> I'm concerned about HSE. Is the bit really a disable bit?
> MIPI_DSI_MODE_VIDEO_HSE is supposed to be an enable flag, so you
> should not do `reg |= DSIM_HSE_DISABLE;`, probably.

I suspect the HSE bit is a misnomer, but its handling in the driver is 
correct.

i.MX 8M Plus Applications Processor Reference Manual, Rev. 1, 06/2021
Page 5436

23 HseDisableMode

In Vsync pulse and Vporch area, MIPI DSI master transfers only Hsync 
start packet to MIPI DSI slave at MIPI DSI spec 1.1r02. This bit 
transfers Hsync end packet in Vsync pulse and Vporch area (optional).

0 = Disables transfer
1 = Enables transfer

In command mode, this bit is ignored.



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