From: David Kershner <david.kersh...@unisys.com>
The new interrupt code was NOT distinguishing between the availability of
an irq (i.e., visor_device.irq != 0), and the fact that we were in fact
operating in real interrupt mode (i.e., request_irq() succeeded). This
could cause us to do the wrong thing in visorbus_enable_channel_interrupts,
visorbus_disable_channel_interrupts and visorbus_rearm_channel_interrupts.
This was fixed by adding a boolean named visor_device.irq_requested, which
is true iff request_irq() succeeded.
We were not properly restoring interrupt-related state after a failed
attempt of visorbus_register_channel_interrupts(), nor after the device
was unattached from a function driver. Most-notably, we did NOT call
free_irq() (the book-end to request_irq()). This was fixed via a new
visorbus_unregister_for_channel_interrupts.
Signed-off-by: David Kershner <david.kersh...@unisys.com>
Signed-off-by: Tim Sell <timothy.s...@unisys.com>
Signed-off-by: Benjamin Romer <benjamin.ro...@unisys.com>
---
drivers/staging/unisys/include/visorbus.h | 2 +
drivers/staging/unisys/visorbus/visorbus_main.c | 65 ++++++++++++++++++++++---
2 files changed, 59 insertions(+), 8 deletions(-)
diff --git a/drivers/staging/unisys/include/visorbus.h
b/drivers/staging/unisys/include/visorbus.h
index e2251f7..23f4704 100644
--- a/drivers/staging/unisys/include/visorbus.h
+++ b/drivers/staging/unisys/include/visorbus.h
@@ -162,6 +162,7 @@ struct visor_device {
int irq;
int wait_ms;
int recv_queue; /* specifies which queue to receive msgs on */
+ bool irq_requested; /* true iff request_irq() succeeded */
};
#define to_visor_device(x) container_of(x, struct visor_device, device)
@@ -181,6 +182,7 @@ int visorbus_registerdevnode(struct visor_device *dev,
const char *name, int major, int minor);
int visorbus_register_for_channel_interrupts(struct visor_device *dev,
u32 queue);
+int visorbus_unregister_for_channel_interrupts(struct visor_device *dev);
void visorbus_enable_channel_interrupts(struct visor_device *dev);
void visorbus_disable_channel_interrupts(struct visor_device *dev);
void visorbus_rearm_channel_interrupts(struct visor_device *dev);
diff --git a/drivers/staging/unisys/visorbus/visorbus_main.c
b/drivers/staging/unisys/visorbus/visorbus_main.c
index 962af12..27aa3df 100644
--- a/drivers/staging/unisys/visorbus/visorbus_main.c
+++ b/drivers/staging/unisys/visorbus/visorbus_main.c
@@ -723,6 +723,14 @@ dev_periodic_work(void *xdev)
struct visor_device *dev = xdev;
struct visor_driver *drv = to_visor_driver(dev->device.driver);
+ /*
+ * Note that channel_interrupt() is called withOUT
+ * visordriver_callback_lock(), unlike the other callbacks. This both
+ * makes the behavior consistent between polling versus NON-polling
+ * modes, and enables us to handle I/Os while in the function driver's
+ * probe() function, which is necessary particularly for the
+ * scsi_scan_host() call in the visorhba case.
+ */
if (drv->channel_interrupt)
drv->channel_interrupt(dev);
}
@@ -734,8 +742,10 @@ dev_start_periodic_work(struct visor_device *dev)
return;
/* now up by at least 2 */
get_device(&dev->device);
- if (!visor_periodic_work_start(dev->periodic_work))
+ if (!visor_periodic_work_start(dev->periodic_work)) {
+ dev_err(&dev->device, "%s failed\n", __func__);
put_device(&dev->device);
+ }
}
static void
@@ -786,13 +796,18 @@ visordriver_probe_device(struct device *xdev)
get_device(&dev->device);
visorbus_set_channel_state(dev, CHANNELCLI_OWNED);
if (!drv->probe) {
+ dev_err(xdev, "%s function driver provide no probe()\n",
+ __func__);
up(&dev->visordriver_callback_lock);
rc = -1;
goto away;
}
rc = drv->probe(dev);
- if (rc < 0)
+ if (rc < 0) {
+ dev_err(xdev, "%s function driver probe() errored\n",
+ __func__);
goto away;
+ }
fix_vbus_dev_info(dev);
up(&dev->visordriver_callback_lock);
@@ -830,6 +845,7 @@ visordriver_remove_device(struct device *xdev)
}
up(&dev->visordriver_callback_lock);
dev_stop_periodic_work(dev);
+ visorbus_unregister_for_channel_interrupts(dev);
devmajorminor_remove_all_files(dev);
visorbus_set_channel_state(dev, CHANNELCLI_ATTACHED);
@@ -964,7 +980,7 @@ EXPORT_SYMBOL_GPL(visorbus_registerdevnode);
void
visorbus_rearm_channel_interrupts(struct visor_device *dev)
{
- if (dev->irq)
+ if (dev->irq_requested)
visorchannel_set_sig_features(dev->visorchannel,
dev->recv_queue,
ULTRA_CHANNEL_ENABLE_INTS);
@@ -976,24 +992,30 @@ EXPORT_SYMBOL_GPL(visorbus_rearm_channel_interrupts);
void
visorbus_enable_channel_interrupts(struct visor_device *dev)
{
- if (dev->irq)
+ if (dev->irq_requested) {
+ dev_dbg(&dev->device, "%s real interrupts\n", __func__);
visorchannel_set_sig_features(dev->visorchannel,
dev->recv_queue,
ULTRA_CHANNEL_ENABLE_INTS);
- else
+ } else {
+ dev_dbg(&dev->device, "%s polling\n", __func__);
dev_start_periodic_work(dev);
+ }
}
EXPORT_SYMBOL_GPL(visorbus_enable_channel_interrupts);
void
visorbus_disable_channel_interrupts(struct visor_device *dev)
{
- if (!dev->irq)
+ if (!dev->irq_requested) {
+ dev_dbg(&dev->device, "%s real interrupts\n", __func__);
visorchannel_clear_sig_features(dev->visorchannel,
dev->recv_queue,
ULTRA_CHANNEL_ENABLE_INTS);
- else
+ } else {
+ dev_dbg(&dev->device, "%s polling\n", __func__);
dev_stop_periodic_work(dev);
+ }
}
EXPORT_SYMBOL_GPL(visorbus_disable_channel_interrupts);
@@ -1074,6 +1096,32 @@ int visorbus_clear_channel_features(struct visor_device
*dev, u64 feature_bits)
return err;
}
+int visorbus_unregister_for_channel_interrupts(struct visor_device *dev)
+{
+ int err = 0;
+
+ if (dev->irq_requested) {
+ free_irq(dev->irq, dev);
+ dev->irq_requested = false;
+ }
+ err = visorbus_set_channel_features(dev, ULTRA_IO_CHANNEL_IS_POLLING);
+ if (err) {
+ dev_err(&dev->device,
+ "%s failed to set polling flag from chan (%d)\n",
+ __func__, err);
+ }
+ err = visorbus_clear_channel_features(dev,
+ ULTRA_IO_DRIVER_ENABLES_INTS |
+ ULTRA_IO_DRIVER_DISABLES_INTS);
+ if (err) {
+ dev_err(&dev->device,
+ "%s failed to clear enable ints from chan (%d)\n",
+ __func__, err);
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(visorbus_unregister_for_channel_interrupts);
+
#define INTERRUPT_VECTOR_MASK 0x3f
int visorbus_register_for_channel_interrupts(struct visor_device *dev,
u32 queue)
@@ -1093,6 +1141,7 @@ int visorbus_register_for_channel_interrupts(struct
visor_device *dev,
}
dev_info(&dev->device, "IRQ=%d registered\n", dev->irq);
+ dev->irq_requested = true;
err = visorbus_set_channel_features(dev, ULTRA_IO_DRIVER_ENABLES_INTS |
ULTRA_IO_DRIVER_DISABLES_INTS);
@@ -1116,7 +1165,7 @@ int visorbus_register_for_channel_interrupts(struct
visor_device *dev,
return 0;
stay_in_polling:
- dev->irq = 0;
+ visorbus_unregister_for_channel_interrupts(dev);
return err;
}
EXPORT_SYMBOL_GPL(visorbus_register_for_channel_interrupts);
--
2.5.0
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