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From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
Subject: [PATCH] mtd: m25p80: use single SPI message for writing data
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
On all 3 tested Northstar devices with following flash memories:
mx25l6405d (8192 Kbytes)
mx25l12805d (16384 Kbytes)
mx25l25635e (32768 Kbytes)
I noticed writing to be broken. Not a single bit was changed leaving all
bytes set to 0xff.
This is most likely some problem related to the SPI controller or its
driver. Using a single SPI message seems to workaround this. Of course
it's not perfect solution as copying whole data into a new buffer makes
writing slower.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
---
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -78,6 +78,7 @@ static ssize_t m25p80_write(struct spi_n
{
struct m25p *flash = nor->priv;
struct spi_device *spi = flash->spi;
+ u8 *command = kzalloc(MAX_CMD_SIZE + len, GFP_KERNEL);
struct spi_transfer t[2] = {};
struct spi_message m;
int cmd_sz = m25p_cmdsz(nor);
@@ -88,24 +89,26 @@ static ssize_t m25p80_write(struct spi_n
if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
cmd_sz = 1;
- flash->command[0] = nor->program_opcode;
- m25p_addr2cmd(nor, to, flash->command);
+ command[0] = nor->program_opcode;
+ m25p_addr2cmd(nor, to, command);
+ memcpy(&command[cmd_sz], buf, len);
- t[0].tx_buf = flash->command;
- t[0].len = cmd_sz;
+ t[0].tx_buf = command;
+ t[0].len = cmd_sz + len;
spi_message_add_tail(&t[0], &m);
- t[1].tx_buf = buf;
- t[1].len = len;
- spi_message_add_tail(&t[1], &m);
-
ret = spi_sync(spi, &m);
- if (ret)
+ if (ret) {
+ kfree(command);
return ret;
+ }
ret = m.actual_length - cmd_sz;
- if (ret < 0)
+ if (ret < 0) {
+ kfree(command);
return -EIO;
+ }
+ kfree(command);
return ret;
}
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