Patch "mtd: rawnand: Fix and simplify again the continuous read derivations" has been added to the 6.6-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is a note to let you know that I've just added the patch titled

    mtd: rawnand: Fix and simplify again the continuous read derivations

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-fix-and-simplify-again-the-continuous-re.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.



commit 1f9686c7177f1ba0384605bae079c5684f2be1df
Author: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Date:   Fri Feb 23 12:55:43 2024 +0100

    mtd: rawnand: Fix and simplify again the continuous read derivations
    
    [ Upstream commit c7ee7c8d4b60fe46d4861b1200bc1c7ab657960a ]
    
    We need to avoid the first page if we don't read it entirely.
    We need to avoid the last page if we don't read it entirely.
    While rather simple, this logic has been failed in the previous
    fix. This time I wrote about 30 unit tests locally to check each
    possible condition, hopefully I covered them all.
    
    Reported-by: Christophe Kerello <christophe.kerello@xxxxxxxxxxx>
    Closes: https://lore.kernel.org/linux-mtd/20240221175327.42f7076d@xps-13/T/#m399bacb10db8f58f6b1f0149a1df867ec086bb0a
    Suggested-by: Christophe Kerello <christophe.kerello@xxxxxxxxxxx>
    Fixes: 828f6df1bcba ("mtd: rawnand: Clarify conditions to enable continuous reads")
    Cc: stable@xxxxxxxxxxxxxxx
    Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
    Tested-by: Christophe Kerello <christophe.kerello@xxxxxxxxxxx>
    Link: https://lore.kernel.org/linux-mtd/20240223115545.354541-2-miquel.raynal@xxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 76167b8ca9dda..9118b5753c553 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -3461,30 +3461,36 @@ static void rawnand_enable_cont_reads(struct nand_chip *chip, unsigned int page,
 				      u32 readlen, int col)
 {
 	struct mtd_info *mtd = nand_to_mtd(chip);
-	unsigned int end_page, end_col;
+	unsigned int first_page, last_page;
 
 	chip->cont_read.ongoing = false;
 
 	if (!chip->controller->supported_op.cont_read)
 		return;
 
-	end_page = DIV_ROUND_UP(col + readlen, mtd->writesize);
-	end_col = (col + readlen) % mtd->writesize;
+	/*
+	 * Don't bother making any calculations if the length is too small.
+	 * Side effect: avoids possible integer underflows below.
+	 */
+	if (readlen < (2 * mtd->writesize))
+		return;
 
+	/* Derive the page where continuous read should start (the first full page read) */
+	first_page = page;
 	if (col)
-		page++;
-
-	if (end_col && end_page)
-		end_page--;
+		first_page++;
 
-	if (page + 1 > end_page)
-		return;
-
-	chip->cont_read.first_page = page;
-	chip->cont_read.last_page = end_page;
-	chip->cont_read.ongoing = true;
+	/* Derive the page where continuous read should stop (the last full page read) */
+	last_page = page + ((col + readlen) / mtd->writesize) - 1;
 
-	rawnand_cap_cont_reads(chip);
+	/* Configure and enable continuous read when suitable */
+	if (first_page < last_page) {
+		chip->cont_read.first_page = first_page;
+		chip->cont_read.last_page = last_page;
+		chip->cont_read.ongoing = true;
+		/* May reset the ongoing flag */
+		rawnand_cap_cont_reads(chip);
+	}
 }
 
 static void rawnand_cont_read_skip_first_page(struct nand_chip *chip, unsigned int page)




[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux