Re: [PATCH v2 2/2] dmaengine: JZ4780: Add support for the JZ4755.

From: Siarhei Volkau
Date: Mon Oct 17 2022 - 13:31:13 EST


пн, 17 окт. 2022 г. в 12:34, Paul Cercueil <paul@xxxxxxxxxxxxxxx>:
> Can you verify that?
>
> It should be pretty simple, if it has the bug you'll see I/O errors on
> the SD card.

Well, the result is ambiguous:

Without that 'broken' flag: mmc works poorly, but becomes more or less
stable when MMC clock downs to 6MHz (90% boots without errors).
On the 12MHz MMC clock the issue doesn't appear in 50-70% cases.
On the 24MHz MMC clock the device never boots up.

However with the flag: MMC works stable on 24MHz MMC clock
(boot issue observed only once), but if I increase MMC clock speed even
a bit the problem appears oftenly ( >70% of cases).

So, that flag definitely helps a lot, but the nature of the problem might be
different.

BR,
Siarhei