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authorJohn W. Linville <linville@tuxdriver.com>2010-03-31 21:39:35 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-10 10:54:17 -0700
commit19bfed793ee38ce027326a3c518ff6201f673a8d (patch)
tree1a5c2a2f0a8aa8e8fe8002a46c45fa8b678ad3c1 /drivers
parent4f824cdefb327963c511434087fc3a8312f0f685 (diff)
ssb: do not read SPROM if it does not exist
commit d53cdbb94a52a920d5420ed64d986c3523a56743 upstream. 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> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
-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 9681536163ca..a55cff8524c7 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 a8dbb06623c9..0e314ddccec2 100644
--- a/drivers/ssb/pci.c
+++ b/drivers/ssb/pci.c
@@ -621,6 +621,11 @@ 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 f2f920fef10d..007bc3a03486 100644
--- a/drivers/ssb/sprom.c
+++ b/drivers/ssb/sprom.c
@@ -176,3 +176,17 @@ 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;
+}