Change the EEPROM read/write timeout behavior so that we can get actual errors rather than just hanging forever.

This commit is contained in:
px4dev 2012-09-09 11:14:54 -07:00
parent 65ecf1b1c1
commit a9c4fabda6
1 changed files with 30 additions and 9 deletions

View File

@ -119,6 +119,13 @@
# define CONFIG_AT24XX_MTD_BLOCKSIZE AT24XX_PAGESIZE
#endif
/* The AT24 does not respond on the bus during write cycles, so we depend on a long
* timeout to detect problems. The max program time is typically ~5ms.
*/
#ifndef CONFIG_AT24XX_WRITE_TIMEOUT_MS
# define CONFIG_AT24XX_WRITE_TIMEOUT_MS 20
#endif
/************************************************************************************
* Private Types
************************************************************************************/
@ -140,6 +147,8 @@ struct at24c_dev_s
perf_counter_t perf_writes;
perf_counter_t perf_resets;
perf_counter_t perf_read_retries;
perf_counter_t perf_read_errors;
perf_counter_t perf_write_errors;
};
/************************************************************************************
@ -262,6 +271,7 @@ static ssize_t at24c_bread(FAR struct mtd_dev_s *dev, off_t startblock,
while (blocksleft-- > 0)
{
uint16_t offset = startblock * priv->pagesize;
unsigned tries = CONFIG_AT24XX_WRITE_TIMEOUT_MS;
addr[1] = offset & 0xff;
addr[0] = (offset >> 8) & 0xff;
@ -269,7 +279,6 @@ static ssize_t at24c_bread(FAR struct mtd_dev_s *dev, off_t startblock,
for (;;)
{
unsigned tries = 50;
perf_begin(priv->perf_reads);
ret = I2C_TRANSFER(priv->dev, &msgv[0], 2);
@ -279,18 +288,19 @@ static ssize_t at24c_bread(FAR struct mtd_dev_s *dev, off_t startblock,
fvdbg("read stall");
usleep(1000);
perf_count(priv->perf_read_retries);
/*
* Kick the bus in case it's stuck.
/* We should normally only be here on the first read after
* a write.
*
* XXX maybe do special first-read handling with optional
* bus reset as well?
*/
perf_count(priv->perf_read_retries);
if (--tries == 0)
{
tries = 50;
up_i2creset(priv->dev);
perf_count(priv->perf_resets);
perf_count(priv->perf_read_errors);
return ERROR;
}
}
startblock++;
@ -350,6 +360,7 @@ static ssize_t at24c_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, size_t
while (blocksleft-- > 0)
{
uint16_t offset = startblock * priv->pagesize;
unsigned tries = CONFIG_AT24XX_WRITE_TIMEOUT_MS;
buf[1] = offset & 0xff;
buf[0] = (offset >> 8) & 0xff;
@ -365,9 +376,17 @@ static ssize_t at24c_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, size_t
if (ret >= 0)
break;
/* XXX probably want a bus reset in here and an eventual timeout */
fvdbg("write stall");
usleep(1000);
/* We expect to see a number of retries per write cycle as we
* poll for write completion.
*/
if (--tries == 0)
{
perf_count(priv->perf_write_errors);
return ERROR;
}
}
startblock++;
@ -496,6 +515,8 @@ FAR struct mtd_dev_s *at24c_initialize(FAR struct i2c_dev_s *dev)
priv->perf_writes = perf_alloc(PC_ELAPSED, "EEPROM write");
priv->perf_resets = perf_alloc(PC_COUNT, "EEPROM reset");
priv->perf_read_retries = perf_alloc(PC_COUNT, "EEPROM read retries");
priv->perf_read_errors = perf_alloc(PC_COUNT, "EEPROM read errors");
priv->perf_write_errors = perf_alloc(PC_COUNT, "EEPROM write errors");
}
/* Return the implementation-specific state structure as the MTD device */