This is a note to let you know that I've just added the patch titled
mtd: rawnand: Clarify conditions to enable continuous reads
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mtd-rawnand-clarify-conditions-to-enable-continuous-reads.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 828f6df1bcba7f64729166efc7086ea657070445 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Date: Fri, 15 Dec 2023 13:32:08 +0100
Subject: mtd: rawnand: Clarify conditions to enable continuous reads
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From: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
commit 828f6df1bcba7f64729166efc7086ea657070445 upstream.
The current logic is probably fine but is a bit convoluted. Plus, we
don't want partial pages to be part of the sequential operation just in
case the core would optimize the page read with a subpage read (which
would break the sequence). This may happen on the first and last page
only, so if the start offset or the end offset is not aligned with a
page boundary, better avoid them to prevent any risk.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 003fe4b9545b ("mtd: rawnand: Support for sequential cache reads")
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Tested-by: Martin Hundebøll <martin@xxxxxxxxxx>
Link: https://lore.kernel.org/linux-mtd/20231215123208.516590-5-miquel.raynal@xxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mtd/nand/raw/nand_base.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -3461,21 +3461,29 @@ static void rawnand_enable_cont_reads(st
u32 readlen, int col)
{
struct mtd_info *mtd = nand_to_mtd(chip);
+ unsigned int end_page, end_col;
+
+ chip->cont_read.ongoing = false;
if (!chip->controller->supported_op.cont_read)
return;
- if ((col && col + readlen < (3 * mtd->writesize)) ||
- (!col && readlen < (2 * mtd->writesize))) {
- chip->cont_read.ongoing = false;
+ end_page = DIV_ROUND_UP(col + readlen, mtd->writesize);
+ end_col = (col + readlen) % mtd->writesize;
+
+ if (col)
+ page++;
+
+ if (end_col && end_page)
+ end_page--;
+
+ if (page + 1 > end_page)
return;
- }
- chip->cont_read.ongoing = true;
chip->cont_read.first_page = page;
- if (col)
- chip->cont_read.first_page++;
- chip->cont_read.last_page = page + ((readlen >> chip->page_shift) & chip->pagemask);
+ chip->cont_read.last_page = end_page;
+ chip->cont_read.ongoing = true;
+
rawnand_cap_cont_reads(chip);
}
Patches currently in stable-queue which might be from miquel.raynal@xxxxxxxxxxx are
queue-6.6/mtd-rawnand-prevent-crossing-lun-boundaries-during-sequential-reads.patch
queue-6.6/mtd-rawnand-fix-core-interference-with-sequential-reads.patch
queue-6.6/mtd-rawnand-clarify-conditions-to-enable-continuous-reads.patch
queue-6.6/mtd-rawnand-prevent-sequential-reads-with-on-die-ecc-engines.patch
queue-6.6/mtd-maps-vmu-flash-fix-the-mtd-core-switch-to-ref-counters.patch
