From d53cdbb94a52a920d5420ed64d986c3523a56743 Mon Sep 17 00:00:00 2001 From: "John W. Linville" Date: Wed, 31 Mar 2010 21:39:35 +0200 Subject: ssb: do not read SPROM if it does not exist MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Attempting to read registers that don't exist on the SSB bus can cause hangs on some boxes. At least some b43 devices are 'in the wild' that don't have SPROMs at all. When the SSB bus support loads, it attempts to read these (non-existant) SPROMs and causes hard hangs on the box -- no console output, etc. This patch adds some intelligence to determine whether or not the SPROM is present before attempting to read it. This avoids those hard hangs on those devices with no SPROM attached to their SSB bus. The SSB-attached devices (e.g. b43, et al.) won't work, but at least the box will survive to test further patches. :-) Signed-off-by: John W. Linville Signed-off-by: Rafał Miłecki Cc: Larry Finger Cc: Michael Buesch --- drivers/ssb/driver_chipcommon.c | 2 ++ drivers/ssb/pci.c | 5 +++++ drivers/ssb/sprom.c | 14 ++++++++++++++ 3 files changed, 21 insertions(+) (limited to 'drivers/ssb') diff --git a/drivers/ssb/driver_chipcommon.c b/drivers/ssb/driver_chipcommon.c index 59c3c0fdbec..59ae76bace1 100644 --- a/drivers/ssb/driver_chipcommon.c +++ b/drivers/ssb/driver_chipcommon.c @@ -233,6 +233,8 @@ void ssb_chipcommon_init(struct ssb_chipcommon *cc) { if (!cc->dev) return; /* We don't have a ChipCommon */ + if (cc->dev->id.revision >= 11) + cc->status = chipco_read32(cc, SSB_CHIPCO_CHIPSTAT); ssb_pmu_init(cc); chipco_powercontrol_init(cc); ssb_chipco_set_clockmode(cc, SSB_CLKMODE_FAST); diff --git a/drivers/ssb/pci.c b/drivers/ssb/pci.c index 9e50896233a..a4b2b99f2c8 100644 --- a/drivers/ssb/pci.c +++ b/drivers/ssb/pci.c @@ -620,6 +620,11 @@ static int ssb_pci_sprom_get(struct ssb_bus *bus, int err = -ENOMEM; u16 *buf; + if (!ssb_is_sprom_available(bus)) { + ssb_printk(KERN_ERR PFX "No SPROM available!\n"); + return -ENODEV; + } + buf = kcalloc(SSB_SPROMSIZE_WORDS_R123, sizeof(u16), GFP_KERNEL); if (!buf) goto out; diff --git a/drivers/ssb/sprom.c b/drivers/ssb/sprom.c index d0e6762fec5..83bc088b941 100644 --- a/drivers/ssb/sprom.c +++ b/drivers/ssb/sprom.c @@ -175,3 +175,17 @@ const struct ssb_sprom *ssb_get_fallback_sprom(void) { return fallback_sprom; } + +/* http://bcm-v4.sipsolutions.net/802.11/IsSpromAvailable */ +bool ssb_is_sprom_available(struct ssb_bus *bus) +{ + /* status register only exists on chipcomon rev >= 11 and we need check + for >= 31 only */ + /* this routine differs from specs as we do not access SPROM directly + on PCMCIA */ + if (bus->bustype == SSB_BUSTYPE_PCI && + bus->chipco.dev->id.revision >= 31) + return bus->chipco.capabilities & SSB_CHIPCO_CAP_SPROM; + + return true; +} -- cgit v1.2.3