When we get an interrupt from the hardware, the first thing we do is
tell the device to mask off the interrupt line. Unfortunately this
transfer ends up happening in interrupt context. Some (most?) SPI
controllers perform the transfer asynchronously. This is bad.
So, work around this by using adding a hwbus hook for the cw1200 driver
core to call. The cw1200_spi driver translates this into
irq_disable()/irq_enable() calls instead.
Apparently the platforms I used to develop the cw1200_spi driver used
synchronous spi_sync() implementations, but not everything is so
blessed.
Signed-off-by: Solomon Peachy <pizza@xxxxxxxxxxxx>
---
drivers/net/wireless/cw1200/cw1200_spi.c | 19 ++++++++++++++++---
drivers/net/wireless/cw1200/fwio.c | 2 +-
drivers/net/wireless/cw1200/hwbus.h | 1 +
drivers/net/wireless/cw1200/hwio.c | 15 +++++++++++++++
4 files changed, 33 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/cw1200/cw1200_spi.c b/drivers/net/wireless/cw1200/cw1200_spi.c
index d063760..c31580b 100644
--- a/drivers/net/wireless/cw1200/cw1200_spi.c
+++ b/drivers/net/wireless/cw1200/cw1200_spi.c
@@ -41,6 +41,7 @@ struct hwbus_priv {
const struct cw1200_platform_data_spi *pdata;
spinlock_t lock; /* Serialize all bus operations */
int claimed;
+ int irq_disabled;
};
#define SDIO_TO_SPI_ADDR(addr) ((addr & 0x1f)>>2)
@@ -230,6 +231,8 @@ static irqreturn_t cw1200_spi_irq_handler(int irq, void *dev_id)
struct hwbus_priv *self = dev_id;
if (self->core) {
+ disable_irq_nosync(self->func->irq);
+ self->irq_disabled = 1;
cw1200_irq_handler(self->core);
return IRQ_HANDLED;
} else {
@@ -263,13 +266,22 @@ exit:
static int cw1200_spi_irq_unsubscribe(struct hwbus_priv *self)
{
- int ret = 0;
-
pr_debug("SW IRQ unsubscribe\n");
disable_irq_wake(self->func->irq);
free_irq(self->func->irq, self);
- return ret;
+ return 0;
+}
+
+static int cw1200_spi_irq_enable(struct hwbus_priv *self, int enable)
+{
+ /* Disables are handled by the interrupt handler */
+ if (enable && self->irq_disabled) {
+ enable_irq(self->func->irq);
+ self->irq_disabled = 0;
+ }
+
+ return 0;
}
static int cw1200_spi_off(const struct cw1200_platform_data_spi *pdata)
@@ -349,6 +361,7 @@ static struct hwbus_ops cw1200_spi_hwbus_ops = {
.unlock = cw1200_spi_unlock,
.align_size = cw1200_spi_align_size,
.power_mgmt = cw1200_spi_pm,
+ .irq_enable = cw1200_spi_irq_enable,
};
/* Probe Function to be called by SPI stack when device is discovered */
diff --git a/drivers/net/wireless/cw1200/fwio.c b/drivers/net/wireless/cw1200/fwio.c
index acdff0f..0b2061b 100644
--- a/drivers/net/wireless/cw1200/fwio.c
+++ b/drivers/net/wireless/cw1200/fwio.c
@@ -485,7 +485,7 @@ int cw1200_load_firmware(struct cw1200_common *priv)
/* Enable interrupt signalling */
priv->hwbus_ops->lock(priv->hwbus_priv);
- ret = __cw1200_irq_enable(priv, 1);
+ ret = __cw1200_irq_enable(priv, 2);
priv->hwbus_ops->unlock(priv->hwbus_priv);
if (ret < 0)
goto unsubscribe;
diff --git a/drivers/net/wireless/cw1200/hwbus.h b/drivers/net/wireless/cw1200/hwbus.h
index 8b2fc83..51dfb3a 100644
--- a/drivers/net/wireless/cw1200/hwbus.h
+++ b/drivers/net/wireless/cw1200/hwbus.h
@@ -28,6 +28,7 @@ struct hwbus_ops {
void (*unlock)(struct hwbus_priv *self);
size_t (*align_size)(struct hwbus_priv *self, size_t size);
int (*power_mgmt)(struct hwbus_priv *self, bool suspend);
+ int (*irq_enable)(struct hwbus_priv *self, int enable);
};
#endif /* CW1200_HWBUS_H */
diff --git a/drivers/net/wireless/cw1200/hwio.c b/drivers/net/wireless/cw1200/hwio.c
index ff230b7..41bd761 100644
--- a/drivers/net/wireless/cw1200/hwio.c
+++ b/drivers/net/wireless/cw1200/hwio.c
@@ -273,6 +273,21 @@ int __cw1200_irq_enable(struct cw1200_common *priv, int enable)
u16 val16;
int ret;
+ /* We need to do this hack because the SPI layer can sleep on I/O
+ and the general path involves I/O to the device in interrupt
+ context.
+
+ However, the initial enable call needs to go to the hardware.
+
+ We don't worry about shutdown because we do a full reset which
+ clears the interrupt enabled bits.
+ */
+ if (priv->hwbus_ops->irq_enable) {
+ ret = priv->hwbus_ops->irq_enable(priv->hwbus_priv, enable);
+ if (ret || enable < 2)
+ return ret;
+ }
+
if (HIF_8601_SILICON == priv->hw_type) {
ret = __cw1200_reg_read_32(priv, ST90TDS_CONFIG_REG_ID, &val32);
if (ret < 0) {
--
1.8.3.1
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html