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authorJohn W. Linville <linville@tuxdriver.com>2010-03-31 21:39:35 +0200
committerJohn W. Linville <linville@tuxdriver.com>2010-04-26 13:50:54 -0400
commitd53cdbb94a52a920d5420ed64d986c3523a56743 (patch)
tree39b1026c953de14ce6b14417cf9bcb66992909f0 /drivers/ssb
parent672724403b42da1d276c6cf811e8e34d15efd964 (diff)
downloadop-kernel-dev-d53cdbb94a52a920d5420ed64d986c3523a56743.zip
op-kernel-dev-d53cdbb94a52a920d5420ed64d986c3523a56743.tar.gz
ssb: do not read SPROM if it does not exist
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 <linville@tuxdriver.com> Signed-off-by: Rafał Miłecki <zajec5@gmail.com> Cc: Larry Finger <Larry.Finger@lwfinger.net> Cc: Michael Buesch <mb@bu3sch.de>
Diffstat (limited to 'drivers/ssb')
-rw-r--r--drivers/ssb/driver_chipcommon.c2
-rw-r--r--drivers/ssb/pci.c5
-rw-r--r--drivers/ssb/sprom.c14
3 files changed, 21 insertions, 0 deletions
diff --git a/drivers/ssb/driver_chipcommon.c b/drivers/ssb/driver_chipcommon.c
index 59c3c0f..59ae76b 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 9e50896..a4b2b99 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 d0e6762..83bc088 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;
+}
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