diff options
author | imp <imp@FreeBSD.org> | 2008-06-06 17:22:07 +0000 |
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committer | imp <imp@FreeBSD.org> | 2008-06-06 17:22:07 +0000 |
commit | c04ec928d613aa12480e10cf22f16ffc324af231 (patch) | |
tree | db9871d1944a773098982497580df5d4386be6af /sys | |
parent | 9b68850f895ae0853b2f24a20dd21f899e1be705 (diff) | |
download | FreeBSD-src-c04ec928d613aa12480e10cf22f16ffc324af231.zip FreeBSD-src-c04ec928d613aa12480e10cf22f16ffc324af231.tar.gz |
o Remove unused cs_debug tunable. I think I added it and then nothing with
it. Bad imp. Removing us dips us under 10,000 in size too.
o Replace an unconditional 30ms DELAY (yes, busy wait) with a check of the
SIBUSY bit in the SelfST register before accessing the eeprom. This changes
the time to read the EEPROM from 2 * 20 * 30ms (1.2s) to < 20*25us (.0005s)
and make the attach of the card tolerable when ethernet media is present.
Include data from the datasheet about why this works. While this is a 2500x
speed increase, it doesn't really matter at all once the card is probed...
o set dev earlier in softc.
Diffstat (limited to 'sys')
-rw-r--r-- | sys/dev/cs/if_cs.c | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/sys/dev/cs/if_cs.c b/sys/dev/cs/if_cs.c index 486481c..950b905 100644 --- a/sys/dev/cs/if_cs.c +++ b/sys/dev/cs/if_cs.c @@ -105,12 +105,6 @@ driver_intr_t csintr; /* sysctl vars */ SYSCTL_NODE(_hw, OID_AUTO, cs, CTLFLAG_RD, 0, "cs device parameters"); -int cs_debug = 0; -TUNABLE_INT("hw.cs.debug", &cs_debug); -SYSCTL_INT(_hw_cs, OID_AUTO, debug, CTLFLAG_RW, - &cs_debug, 0, - "cs debug"); - int cs_ignore_cksum_failure = 0; TUNABLE_INT("hw.cs.ignore_checksum_failure", &cs_ignore_cksum_failure); SYSCTL_INT(_hw_cs, OID_AUTO, ignore_checksum_failure, CTLFLAG_RW, @@ -137,9 +131,8 @@ get_eeprom_data(struct cs_softc *sc, int off, int len, uint16_t *buffer) int i; #ifdef CS_DEBUG - device_printf(sc->sc_dev, "EEPROM data from %x for %x:\n", off, len); + device_printf(sc->dev, "EEPROM data from %x for %x:\n", off, len); #endif - for (i=0; i < len; i++) { if (wait_eeprom_ready(sc) < 0) return (-1); @@ -177,8 +170,26 @@ get_eeprom_cksum(int off, int len, uint16_t *buffer) static int wait_eeprom_ready(struct cs_softc *sc) { - DELAY(30000); /* XXX should we do some checks here ? */ - return (0); + int i; + + /* + * From the CS8900A datasheet, section 3.5.2: + * "Before issuing any command to the EEPROM, the host must wait + * for the SIBUSY bit (Register 16, SelfST, bit 8) to clear. After + * each command has been issued, the host must wait again for SIBUSY + * to clear." + * + * Before we issue the command, we should be !busy, so that will + * be fast. The datasheet suggests that clock out from the part + * per word will be on the order of 25us, which is consistant with + * the 1MHz serial clock and 16bits... We should never hit 100, + * let alone 30,000 here. The original code did an unconditional + * 30ms DELAY here. Bad Kharma. + */ + for (i = 0; i < 30000; i++) /* 30ms max */ + if (!(cs_readreg(sc, PP_SelfST) & SI_BUSY)) + return (0); + return (1); } static void @@ -256,6 +267,7 @@ cs_cs89x0_probe(device_t dev) uint16_t eeprom_buff[CHKSUM_LEN]; int chip_type, pp_isaint, pp_isadma; + sc->dev = dev; error = cs_alloc_port(dev, 0, CS_89x0_IO_PORTS); if (error) return (error); |