[PATCH] mmc: rockchip_sdhci: Revert 4 blocks PIO mode read limit for RK35xx

[Quentin Schulz]

Hi Jonas,

On 3/27/24 00:35, Jonas Karlman wrote:
> The commit 2cc6cde647e2 ("mmc: rockchip_sdhci: Limit number of blocks
> read in a single command") introduced a limit of number of blocks to
> read to fix a Data End Bit Error on RK3568 and RK3588. This had a side
> affect of significant slowing down reading FIT from eMMC.
> 
> After the commit 6de9d7b2f13c ("rockchip: rk35xx: Enable eMMC HS200 mode
> by default") the limit of number of blocks to read workaround is no
> longer necessary and a Data End Bit Error is no longer happening using
> PIO mode.
> 
> Revert this limitation to allow reading more than 4 blocks with a single
> CMD18 command in PIO mode and speed up reading FIT from eMMC.
> 

Should we instead keep this code but surround it with
#if !IS_ENABLED(MMC_HS200_SUPPORT)
?

After all, HS200 is only implied for RK35xx boards, so one could disable it.

Also wondering whether we should do this dynamically based on the MMC 
mode that could be negotiated with the chip? E.g. I think it's not 
guaranteed that with hs200 support built and enabled in DT that it'll be 
negotiated as HS200?

Cheers,
Quentin