On Friday 06 November 2009 19:27:17 Martin Fuzzey wrote:
> > I think this is easy to fix, because we can replace the spinlock by a mutex, as
> > the b43 driver (which is the only user of the code) always allows sleeping now.
> > I'll send a patch for testing soon.
> >
> Great - happy to test it.
There you go. Note that I did not test it, as trying to use my pcmcia card throws
a hell of a lot oopses at me and the firmware finally force-resets the hardware
for some reason. This needs some debugging first...
Index: wireless-testing/drivers/ssb/main.c
===================================================================
--- wireless-testing.orig/drivers/ssb/main.c 2009-10-09 19:50:16.000000000 +0200
+++ wireless-testing/drivers/ssb/main.c 2009-11-06 19:47:18.000000000 +0100
@@ -740,7 +740,7 @@ static int ssb_bus_register(struct ssb_b
{
int err;
- spin_lock_init(&bus->bar_lock);
+ mutex_init(&bus->register_mutex);
INIT_LIST_HEAD(&bus->list);
#ifdef CONFIG_SSB_EMBEDDED
spin_lock_init(&bus->gpio_lock);
Index: wireless-testing/drivers/ssb/pcmcia.c
===================================================================
--- wireless-testing.orig/drivers/ssb/pcmcia.c 2009-07-28 22:53:08.000000000 +0200
+++ wireless-testing/drivers/ssb/pcmcia.c 2009-11-06 19:35:59.000000000 +0100
@@ -238,15 +238,14 @@ static int select_core_and_segment(struc
static u8 ssb_pcmcia_read8(struct ssb_device *dev, u16 offset)
{
struct ssb_bus *bus = dev->bus;
- unsigned long flags;
int err;
u8 value = 0xFF;
- spin_lock_irqsave(&bus->bar_lock, flags);
+ mutex_lock(&bus->register_mutex);
err = select_core_and_segment(dev, &offset);
if (likely(!err))
value = readb(bus->mmio + offset);
- spin_unlock_irqrestore(&bus->bar_lock, flags);
+ mutex_unlock(&bus->register_mutex);
return value;
}
@@ -254,15 +253,14 @@ static u8 ssb_pcmcia_read8(struct ssb_de
static u16 ssb_pcmcia_read16(struct ssb_device *dev, u16 offset)
{
struct ssb_bus *bus = dev->bus;
- unsigned long flags;
int err;
u16 value = 0xFFFF;
- spin_lock_irqsave(&bus->bar_lock, flags);
+ mutex_lock(&bus->register_mutex);
err = select_core_and_segment(dev, &offset);
if (likely(!err))
value = readw(bus->mmio + offset);
- spin_unlock_irqrestore(&bus->bar_lock, flags);
+ mutex_unlock(&bus->register_mutex);
return value;
}
@@ -270,17 +268,16 @@ static u16 ssb_pcmcia_read16(struct ssb_
static u32 ssb_pcmcia_read32(struct ssb_device *dev, u16 offset)
{
struct ssb_bus *bus = dev->bus;
- unsigned long flags;
int err;
u32 lo = 0xFFFFFFFF, hi = 0xFFFFFFFF;
- spin_lock_irqsave(&bus->bar_lock, flags);
+ mutex_lock(&bus->register_mutex);
err = select_core_and_segment(dev, &offset);
if (likely(!err)) {
lo = readw(bus->mmio + offset);
hi = readw(bus->mmio + offset + 2);
}
- spin_unlock_irqrestore(&bus->bar_lock, flags);
+ mutex_unlock(&bus->register_mutex);
return (lo | (hi << 16));
}
@@ -290,11 +287,10 @@ static void ssb_pcmcia_block_read(struct
size_t count, u16 offset, u8 reg_width)
{
struct ssb_bus *bus = dev->bus;
- unsigned long flags;
void __iomem *addr = bus->mmio + offset;
int err;
- spin_lock_irqsave(&bus->bar_lock, flags);
+ mutex_lock(&bus->register_mutex);
err = select_core_and_segment(dev, &offset);
if (unlikely(err)) {
memset(buffer, 0xFF, count);
@@ -339,52 +335,49 @@ static void ssb_pcmcia_block_read(struct
SSB_WARN_ON(1);
}
unlock:
- spin_unlock_irqrestore(&bus->bar_lock, flags);
+ mutex_unlock(&bus->register_mutex);
}
#endif /* CONFIG_SSB_BLOCKIO */
static void ssb_pcmcia_write8(struct ssb_device *dev, u16 offset, u8 value)
{
struct ssb_bus *bus = dev->bus;
- unsigned long flags;
int err;
- spin_lock_irqsave(&bus->bar_lock, flags);
+ mutex_lock(&bus->register_mutex);
err = select_core_and_segment(dev, &offset);
if (likely(!err))
writeb(value, bus->mmio + offset);
mmiowb();
- spin_unlock_irqrestore(&bus->bar_lock, flags);
+ mutex_unlock(&bus->register_mutex);
}
static void ssb_pcmcia_write16(struct ssb_device *dev, u16 offset, u16 value)
{
struct ssb_bus *bus = dev->bus;
- unsigned long flags;
int err;
- spin_lock_irqsave(&bus->bar_lock, flags);
+ mutex_lock(&bus->register_mutex);
err = select_core_and_segment(dev, &offset);
if (likely(!err))
writew(value, bus->mmio + offset);
mmiowb();
- spin_unlock_irqrestore(&bus->bar_lock, flags);
+ mutex_unlock(&bus->register_mutex);
}
static void ssb_pcmcia_write32(struct ssb_device *dev, u16 offset, u32 value)
{
struct ssb_bus *bus = dev->bus;
- unsigned long flags;
int err;
- spin_lock_irqsave(&bus->bar_lock, flags);
+ mutex_lock(&bus->register_mutex);
err = select_core_and_segment(dev, &offset);
if (likely(!err)) {
writew((value & 0x0000FFFF), bus->mmio + offset);
writew(((value & 0xFFFF0000) >> 16), bus->mmio + offset + 2);
}
mmiowb();
- spin_unlock_irqrestore(&bus->bar_lock, flags);
+ mutex_unlock(&bus->register_mutex);
}
#ifdef CONFIG_SSB_BLOCKIO
@@ -392,11 +385,10 @@ static void ssb_pcmcia_block_write(struc
size_t count, u16 offset, u8 reg_width)
{
struct ssb_bus *bus = dev->bus;
- unsigned long flags;
void __iomem *addr = bus->mmio + offset;
int err;
- spin_lock_irqsave(&bus->bar_lock, flags);
+ mutex_lock(&bus->register_mutex);
err = select_core_and_segment(dev, &offset);
if (unlikely(err))
goto unlock;
@@ -440,7 +432,7 @@ static void ssb_pcmcia_block_write(struc
}
unlock:
mmiowb();
- spin_unlock_irqrestore(&bus->bar_lock, flags);
+ mutex_unlock(&bus->register_mutex);
}
#endif /* CONFIG_SSB_BLOCKIO */
Index: wireless-testing/include/linux/ssb/ssb.h
===================================================================
--- wireless-testing.orig/include/linux/ssb/ssb.h 2009-11-01 13:58:49.000000000 +0100
+++ wireless-testing/include/linux/ssb/ssb.h 2009-11-06 19:32:32.000000000 +0100
@@ -278,9 +278,8 @@ struct ssb_bus {
/* Current SSB base address window for SDIO. */
u32 sdio_sbaddr;
};
- /* Lock for core and segment switching.
- * On PCMCIA-host busses this is used to protect the whole MMIO access. */
- spinlock_t bar_lock;
+ /* Mutex to enforce one hardware register read/write is an atomic operation. */
+ struct mutex register_mutex;
/* The host-bus this backplane is running on. */
enum ssb_bustype bustype;
Index: wireless-testing/drivers/ssb/pci.c
===================================================================
--- wireless-testing.orig/drivers/ssb/pci.c 2009-10-09 19:50:16.000000000 +0200
+++ wireless-testing/drivers/ssb/pci.c 2009-11-06 20:04:11.000000000 +0100
@@ -63,7 +63,6 @@ int ssb_pci_switch_core(struct ssb_bus *
struct ssb_device *dev)
{
int err;
- unsigned long flags;
#if SSB_VERBOSE_PCICORESWITCH_DEBUG
ssb_printk(KERN_INFO PFX
@@ -72,11 +71,9 @@ int ssb_pci_switch_core(struct ssb_bus *
dev->core_index);
#endif
- spin_lock_irqsave(&bus->bar_lock, flags);
err = ssb_pci_switch_coreidx(bus, dev->core_index);
if (!err)
bus->mapped_device = dev;
- spin_unlock_irqrestore(&bus->bar_lock, flags);
return err;
}
--
Greetings, Michael.
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