openwrt/target/linux/brcm63xx/patches-4.4/000-4.8-09-mtd-spi-nor-add-read-loop.patch
Jonas Gorski 2a2b16210b brcm63xx: backport upstream solution for SPI message size limits
Backport upstream solution for working around SPI controller maximum
message sizes.

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
2017-06-04 10:40:00 +02:00

55 lines
1.5 KiB
Diff

From 26f9bcad29a6c240881bd4efc90f16a9990dd6c2 Mon Sep 17 00:00:00 2001
From: Michal Suchanek <hramrach@gmail.com>
Date: Thu, 5 May 2016 17:31:55 -0700
Subject: [PATCH 09/10] mtd: spi-nor: add read loop
mtdblock and ubi do not handle the situation when read returns less data
than requested. Loop in spi-nor until buffer is filled or an error is
returned.
Signed-off-by: Michal Suchanek <hramrach@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Tested-by Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Michal Suchanek <hramrach@gmail.com>
Tested-by: Michal Suchanek <hramrach@gmail.com>
---
drivers/mtd/spi-nor/spi-nor.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -890,14 +890,27 @@ static int spi_nor_read(struct mtd_info
if (ret)
return ret;
- ret = nor->read(nor, from, len, buf);
+ while (len) {
+ ret = nor->read(nor, from, len, buf);
+ if (ret == 0) {
+ /* We shouldn't see 0-length reads */
+ ret = -EIO;
+ goto read_err;
+ }
+ if (ret < 0)
+ goto read_err;
- spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_READ);
- if (ret < 0)
- return ret;
+ WARN_ON(ret > len);
+ *retlen += ret;
+ buf += ret;
+ from += ret;
+ len -= ret;
+ }
+ ret = 0;
- *retlen += ret;
- return 0;
+read_err:
+ spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_READ);
+ return ret;
}
static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,