Re: [PATCH v7 2/3] mtd: rawnand: Enable monolithic read when reading subpages

From: Miquel Raynal
Date: Mon May 06 2024 - 03:18:00 EST


Hi,

devnull+keguang.zhang.gmail.com@xxxxxxxxxx wrote on Tue, 30 Apr 2024
19:11:11 +0800:

> From: Keguang Zhang <keguang.zhang@xxxxxxxxx>
>
> nand_read_subpage() reads data and ECC data by two separate
> operations.
> This patch allows the NAND controllers who support
> monolithic page read to do subpage read by a single operation,
> which is more effective than nand_read_subpage().

I am a bit puzzled by this change. Usually nand_read_subpage is used
for optimizations (when less data than a full page must be retrieved).
I know it may be used in other cases (because it's easier for the core
in order to support a wide range of controllers). Can you please show a
speed test showing the results before I consider merging this patch?

The monolithic thing was not supposed to improve throughput but to help
with very limited controllers.

Thanks,
Miquèl