mirror of
git://git.openwrt.org/openwrt/openwrt.git
synced 2025-12-08 21:52:09 -05:00
32229a4bb7
Continuous reading mode is broken for some spi controllers. There are two possible bug scenarios: 1) "continuous mode" flash and spi controller without dirmap support, but with restriction on transfer length in adjust_op_size() 2) "continuous mode" flash and spi controller with dirmap support for a single flash page In the first case, any read that exceeds the limit specified in adjust_op_size() will result in an EIO error. The limit may even be less than a size of a single flash page. In this case, any read will result in an error. In the second case, any read larger than flash page size will result in an EIO error or spinand driver spoofing (because the spi controller driver returns more bytes than were actually read). This patch series tries to fix continuous reading (spinand driver side). Unfortunately these fixes can't resolve "spinand driver spoofing" case. Spi controller drivers might need fixes as well. Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu> Link: https://github.com/openwrt/openwrt/pull/20295 Signed-off-by: Robert Marko <robimarko@gmail.com>
98 lines
3.3 KiB
Diff
98 lines
3.3 KiB
Diff
From 9d13b7857de8834c6246fa5bc83f767675360240 Mon Sep 17 00:00:00 2001
|
|
From: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
|
|
Date: Sun, 3 Aug 2025 19:06:40 +0300
|
|
Subject: [PATCH RESEND v5 2/3] mtd: spinand: try a regular dirmap if creating
|
|
a dirmap for continuous reading fails
|
|
|
|
Continuous reading may result in multiple flash pages reading in one
|
|
operation. Typically only one flash page has read/written (a little bit
|
|
more than 2-4 Kb), but continuous reading requires the spi controller
|
|
to read up to 512 Kb in one operation without toggling CS in beetween.
|
|
|
|
Roughly speaking spi controllers can be divided on 2 categories:
|
|
* spi controllers without dirmap acceleration support
|
|
* spi controllers with dirmap acceleration support
|
|
|
|
Firt of them will have issues with continuous reading if restriction on
|
|
the transfer length is implemented in the adjust_op_size() handler.
|
|
Second group often supports acceleration of single page only reading.
|
|
Thus enabling of continuous reading can break flash reading.
|
|
|
|
This patch tries to create dirmap for continuous reading first and
|
|
fallback to regular reading if spi controller refuses to create it.
|
|
|
|
Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
|
|
---
|
|
drivers/mtd/nand/spi/core.c | 43 ++++++++++++++++++++++++++++++-------
|
|
1 file changed, 35 insertions(+), 8 deletions(-)
|
|
|
|
--- a/drivers/mtd/nand/spi/core.c
|
|
+++ b/drivers/mtd/nand/spi/core.c
|
|
@@ -1024,6 +1024,39 @@ static int spinand_mtd_block_isreserved(
|
|
return ret;
|
|
}
|
|
|
|
+static struct spi_mem_dirmap_desc *spinand_create_rdesc(
|
|
+ struct spinand_device *spinand,
|
|
+ struct spi_mem_dirmap_info *info)
|
|
+{
|
|
+ struct nand_device *nand = spinand_to_nand(spinand);
|
|
+ struct spi_mem_dirmap_desc *desc = NULL;
|
|
+
|
|
+ if (spinand->cont_read_possible) {
|
|
+ /*
|
|
+ * spi controller may return an error if info->length is
|
|
+ * too large
|
|
+ */
|
|
+ info->length = nanddev_eraseblock_size(nand);
|
|
+ desc = devm_spi_mem_dirmap_create(&spinand->spimem->spi->dev,
|
|
+ spinand->spimem, info);
|
|
+ }
|
|
+
|
|
+ if (IS_ERR_OR_NULL(desc)) {
|
|
+ /*
|
|
+ * continuous reading is not supported by flash or
|
|
+ * its spi controller, use regular reading
|
|
+ */
|
|
+ spinand->cont_read_possible = false;
|
|
+
|
|
+ info->length = nanddev_page_size(nand) +
|
|
+ nanddev_per_page_oobsize(nand);
|
|
+ desc = devm_spi_mem_dirmap_create(&spinand->spimem->spi->dev,
|
|
+ spinand->spimem, info);
|
|
+ }
|
|
+
|
|
+ return desc;
|
|
+}
|
|
+
|
|
static int spinand_create_dirmap(struct spinand_device *spinand,
|
|
unsigned int plane)
|
|
{
|
|
@@ -1043,11 +1076,8 @@ static int spinand_create_dirmap(struct
|
|
|
|
spinand->dirmaps[plane].wdesc = desc;
|
|
|
|
- if (spinand->cont_read_possible)
|
|
- info.length = nanddev_eraseblock_size(nand);
|
|
info.op_tmpl = *spinand->op_templates.read_cache;
|
|
- desc = devm_spi_mem_dirmap_create(&spinand->spimem->spi->dev,
|
|
- spinand->spimem, &info);
|
|
+ desc = spinand_create_rdesc(spinand, &info);
|
|
if (IS_ERR(desc))
|
|
return PTR_ERR(desc);
|
|
|
|
@@ -1070,12 +1100,9 @@ static int spinand_create_dirmap(struct
|
|
|
|
spinand->dirmaps[plane].wdesc_ecc = desc;
|
|
|
|
- if (spinand->cont_read_possible)
|
|
- info.length = nanddev_eraseblock_size(nand);
|
|
info.op_tmpl = *spinand->op_templates.read_cache;
|
|
info.op_tmpl.data.ecc = true;
|
|
- desc = devm_spi_mem_dirmap_create(&spinand->spimem->spi->dev,
|
|
- spinand->spimem, &info);
|
|
+ desc = spinand_create_rdesc(spinand, &info);
|
|
if (IS_ERR(desc))
|
|
return PTR_ERR(desc);
|
|
|