diff options
author | Ben Dooks <ben-linux@fluff.org> | 2008-02-05 00:02:17 +0000 |
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committer | Jeff Garzik <jeff@garzik.org> | 2008-02-11 11:06:33 -0500 |
commit | 39c341a8dcf060b246b0beddac90cd7de11d4a20 (patch) | |
tree | b71d29ba042edcd2dbb19da2f783eff4d27fd3a7 /drivers | |
parent | c991d168cb649d416c5a773a50d0754299f31366 (diff) | |
download | op-kernel-dev-39c341a8dcf060b246b0beddac90cd7de11d4a20.zip op-kernel-dev-39c341a8dcf060b246b0beddac90cd7de11d4a20.tar.gz |
DM9000: Fix delays used by EEPROM read and write
The code was using a delay of 8ms, when it should have been
using the EEPROM status flag from the device to indicate the
EEPROM transaction had finished.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/net/dm9000.c | 54 |
1 files changed, 51 insertions, 3 deletions
diff --git a/drivers/net/dm9000.c b/drivers/net/dm9000.c index 8516183..1d790a8 100644 --- a/drivers/net/dm9000.c +++ b/drivers/net/dm9000.c @@ -1048,6 +1048,50 @@ dm9000_rx(struct net_device *dev) } while (rxbyte == DM9000_PKT_RDY); } +static unsigned int +dm9000_read_locked(board_info_t *db, int reg) +{ + unsigned long flags; + unsigned int ret; + + spin_lock_irqsave(&db->lock, flags); + ret = ior(db, reg); + spin_unlock_irqrestore(&db->lock, flags); + + return ret; +} + +static int dm9000_wait_eeprom(board_info_t *db) +{ + unsigned int status; + int timeout = 8; /* wait max 8msec */ + + /* The DM9000 data sheets say we should be able to + * poll the ERRE bit in EPCR to wait for the EEPROM + * operation. From testing several chips, this bit + * does not seem to work. + * + * We attempt to use the bit, but fall back to the + * timeout (which is why we do not return an error + * on expiry) to say that the EEPROM operation has + * completed. + */ + + while (1) { + status = dm9000_read_locked(db, DM9000_EPCR); + + if ((status & EPCR_ERRE) == 0) + break; + + if (timeout-- < 0) { + dev_dbg(db->dev, "timeout waiting EEPROM\n"); + break; + } + } + + return 0; +} + /* * Read a word data from EEPROM */ @@ -1065,8 +1109,10 @@ dm9000_read_eeprom(board_info_t *db, int offset, u8 *to) spin_unlock_irqrestore(&db->lock, flags); - mdelay(8); /* according to the datasheet 200us should be enough, - but it doesn't work */ + dm9000_wait_eeprom(db); + + /* delay for at-least 150uS */ + msleep(1); spin_lock_irqsave(&db->lock, flags); @@ -1097,7 +1143,9 @@ dm9000_write_eeprom(board_info_t *db, int offset, u8 *data) iow(db, DM9000_EPCR, EPCR_WEP | EPCR_ERPRW); spin_unlock_irqrestore(&db->lock, flags); - mdelay(8); /* same shit */ + dm9000_wait_eeprom(db); + + mdelay(1); /* wait at least 150uS to clear */ spin_lock_irqsave(&db->lock, flags); iow(db, DM9000_EPCR, 0); |