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mripard / sunxi-mali

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README.md: add note to define CMA Size in both Linux config or Linux command line #91

Closed giuliobenetti closed 1 year ago

giuliobenetti commented 3 years ago

Add note to define cma=256M if not hardcoded in defconfig or to define it harcoded but with 256M value instead of defaulted 16M that doesn't allow sunxi-mali to work leading to a blanck screen.

Signed-off-by: Giulio Benetti giulio.benetti@benettiengineering.com

hor63 commented 3 years ago

Please mention the config parameter where the value can be hardcoded into the kernel instead of the Kernel parameters from U-Boot.

giuliobenetti commented 3 years ago

It is CMASIZE*specified in the Patchself itself. Also now it can be set in percentage and size. I can modify with that, but in some way it's already there. What about that? And is that what you mean with Kernel config, right? Maybe I have to add at least the prefix CONFIG_, please let me know what you see more understandable.

Thanks

giuliobenetti commented 3 years ago

@hor63 I've just updated commit and commit log. It seems more clear now.

hor63 commented 3 years ago

Perfect. Many thanks. BTW: I found the hint to increase CMA in this comment on #54. Up to kernel 4.18 CMA=128M did the job. My original .config came from 4.17 times, and somehow it was set this way there. 4.19 brought the known regression with Mali, so bisecting the kernel lead nowhere except the hard crashes which were described in #54. After 4.20 128MB CMA was no longer sufficient.

giuliobenetti commented 3 years ago

Good to know. I've honestly used 256M only on A20 and A33 and everything worked fine. But now you've pointed this detailed infos. Thank you!

giuliobenetti commented 3 years ago

This PR solves #90