drm/i915: Add debugfs entry to read/write next_seqno

This is needed for testing seqno wrapping. Be careful to not bump next_seqno
more than 0x7FFFFFFF at a time (between some handled requests) as
i915_seqno_passed() can't handle bigger difference in between.

v2: Address review comments from Chris Wilson.

Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Squash in fixup to properly remove the debugfs file on driver
unload again.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Mika Kuoppala 2012-12-04 15:12:00 +02:00 committed by Daniel Vetter
parent 1a240d4de2
commit 40633219a0

View file

@ -843,6 +843,86 @@ static const struct file_operations i915_error_state_fops = {
.release = i915_error_state_release,
};
static ssize_t
i915_next_seqno_read(struct file *filp,
char __user *ubuf,
size_t max,
loff_t *ppos)
{
struct drm_device *dev = filp->private_data;
drm_i915_private_t *dev_priv = dev->dev_private;
char buf[80];
int len;
int ret;
ret = mutex_lock_interruptible(&dev->struct_mutex);
if (ret)
return ret;
len = snprintf(buf, sizeof(buf),
"next_seqno : 0x%x\n",
dev_priv->next_seqno);
mutex_unlock(&dev->struct_mutex);
if (len > sizeof(buf))
len = sizeof(buf);
return simple_read_from_buffer(ubuf, max, ppos, buf, len);
}
static ssize_t
i915_next_seqno_write(struct file *filp,
const char __user *ubuf,
size_t cnt,
loff_t *ppos)
{
struct drm_device *dev = filp->private_data;
drm_i915_private_t *dev_priv = dev->dev_private;
char buf[20];
u32 val = 1;
int ret;
if (cnt > 0) {
if (cnt > sizeof(buf) - 1)
return -EINVAL;
if (copy_from_user(buf, ubuf, cnt))
return -EFAULT;
buf[cnt] = 0;
ret = kstrtouint(buf, 0, &val);
if (ret < 0)
return ret;
}
if (val == 0)
return -EINVAL;
ret = mutex_lock_interruptible(&dev->struct_mutex);
if (ret)
return ret;
if (i915_seqno_passed(val, dev_priv->next_seqno)) {
dev_priv->next_seqno = val;
DRM_DEBUG_DRIVER("Advancing seqno to %u\n", val);
} else {
ret = -EINVAL;
}
mutex_unlock(&dev->struct_mutex);
return ret ?: cnt;
}
static const struct file_operations i915_next_seqno_fops = {
.owner = THIS_MODULE,
.open = simple_open,
.read = i915_next_seqno_read,
.write = i915_next_seqno_write,
.llseek = default_llseek,
};
static int i915_rstdby_delays(struct seq_file *m, void *unused)
{
struct drm_info_node *node = (struct drm_info_node *) m->private;
@ -2107,6 +2187,12 @@ int i915_debugfs_init(struct drm_minor *minor)
if (ret)
return ret;
ret = i915_debugfs_create(minor->debugfs_root, minor,
"i915_next_seqno",
&i915_next_seqno_fops);
if (ret)
return ret;
return drm_debugfs_create_files(i915_debugfs_list,
I915_DEBUGFS_ENTRIES,
minor->debugfs_root, minor);
@ -2130,6 +2216,8 @@ void i915_debugfs_cleanup(struct drm_minor *minor)
1, minor);
drm_debugfs_remove_files((struct drm_info_list *) &i915_error_state_fops,
1, minor);
drm_debugfs_remove_files((struct drm_info_list *) &i915_next_seqno_fops,
1, minor);
}
#endif /* CONFIG_DEBUG_FS */