On Fri, Apr 27, 2012 at 03:17:40PM +0200, Daniel Vetter wrote:
> ... by writing (anything) to i915_error_state.
>
> This way we can simulate a bunch of gpu hangs and run the error_state
> capture code every time (without the need to reload the module).
>
> To make that happen we need to abandon the simple seq_file wrappers
> provided by the drm core. While at it, but the new error_state
> refcounting to some good use and associated. This should help greatly
> when we finally get around to split up the giant single seq_file block
> that the error_state file currently is into smaller parts.
Meh, commit msg fail, that phrase should read "While at it put the new
error_state refcounting to some good use and associated the error_state to
the debugfs when opening the file. Otherwise the error_state could change
while someone is reading it. This should help greatly ..."
-Daniel
>
> v2: Actually squash all the fixes into the patch ...
>
> Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 90 ++++++++++++++++++++++++++++++-----
> 1 files changed, 77 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index b46c198..4805df0 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -691,21 +691,19 @@ static void i915_ring_error_state(struct seq_file *m,
> seq_printf(m, " ring->tail: 0x%08x\n", error->cpu_ring_tail[ring]);
> }
>
> +struct i915_error_state_file_priv {
> + struct drm_device *dev;
> + struct drm_i915_error_state *error;
> +};
> +
> static int i915_error_state(struct seq_file *m, void *unused)
> {
> - struct drm_info_node *node = (struct drm_info_node *) m->private;
> - struct drm_device *dev = node->minor->dev;
> + struct i915_error_state_file_priv *error_priv = m->private;
> + struct drm_device *dev = error_priv->dev;
> drm_i915_private_t *dev_priv = dev->dev_private;
> - struct drm_i915_error_state *error;
> - unsigned long flags;
> + struct drm_i915_error_state *error = error_priv->error;
> int i, j, page, offset, elt;
>
> - spin_lock_irqsave(&dev_priv->error_lock, flags);
> - error = dev_priv->first_error;
> - if (error)
> - kref_get(&error->ref);
> - spin_unlock_irqrestore(&dev_priv->error_lock, flags);
> -
> if (!error) {
> seq_printf(m, "no error state collected\n");
> return 0;
> @@ -792,11 +790,71 @@ static int i915_error_state(struct seq_file *m, void *unused)
> if (error->display)
> intel_display_print_error_state(m, dev, error->display);
>
> - kref_put(&error->ref, i915_error_state_free);
> -
> return 0;
> }
>
> +static ssize_t
> +i915_error_state_write(struct file *filp,
> + const char __user *ubuf,
> + size_t cnt,
> + loff_t *ppos)
> +{
> + struct seq_file *m = filp->private_data;
> + struct i915_error_state_file_priv *error_priv = m->private;
> + struct drm_device *dev = error_priv->dev;
> +
> + DRM_DEBUG_DRIVER("Resetting error state\n");
> +
> + mutex_lock(&dev->struct_mutex);
> + i915_destroy_error_state(dev);
> + mutex_unlock(&dev->struct_mutex);
> +
> + return cnt;
> +}
> +
> +static int i915_error_state_open(struct inode *inode, struct file *file)
> +{
> + struct drm_device *dev = inode->i_private;
> + drm_i915_private_t *dev_priv = dev->dev_private;
> + struct i915_error_state_file_priv *error_priv;
> + unsigned long flags;
> +
> + error_priv = kzalloc(sizeof(*error_priv), GFP_KERNEL);
> + if (!error_priv)
> + return -ENOMEM;
> +
> + error_priv->dev = dev;
> +
> + spin_lock_irqsave(&dev_priv->error_lock, flags);
> + error_priv->error = dev_priv->first_error;
> + if (error_priv->error)
> + kref_get(&error_priv->error->ref);
> + spin_unlock_irqrestore(&dev_priv->error_lock, flags);
> +
> + return single_open(file, i915_error_state, error_priv);
> +}
> +
> +static int i915_error_state_release(struct inode *inode, struct file *file)
> +{
> + struct seq_file *m = file->private_data;
> + struct i915_error_state_file_priv *error_priv = m->private;
> +
> + if (error_priv->error)
> + kref_put(&error_priv->error->ref, i915_error_state_free);
> + kfree(error_priv);
> +
> + return single_release(inode, file);
> +}
> +
> +static const struct file_operations i915_error_state_fops = {
> + .owner = THIS_MODULE,
> + .open = i915_error_state_open,
> + .read = seq_read,
> + .write = i915_error_state_write,
> + .llseek = default_llseek,
> + .release = i915_error_state_release,
> +};
> +
> static int i915_rstdby_delays(struct seq_file *m, void *unused)
> {
> struct drm_info_node *node = (struct drm_info_node *) m->private;
> @@ -1645,6 +1703,7 @@ static const struct file_operations i915_ring_stop_fops = {
> .write = i915_ring_stop_write,
> .llseek = default_llseek,
> };
> +
> static ssize_t
> i915_max_freq_read(struct file *filp,
> char __user *ubuf,
> @@ -1899,7 +1958,6 @@ static struct drm_info_list i915_debugfs_list[] = {
> {"i915_gem_hws", i915_hws_info, 0, (void *)RCS},
> {"i915_gem_hws_blt", i915_hws_info, 0, (void *)BCS},
> {"i915_gem_hws_bsd", i915_hws_info, 0, (void *)VCS},
> - {"i915_error_state", i915_error_state, 0},
> {"i915_rstdby_delays", i915_rstdby_delays, 0},
> {"i915_cur_delayinfo", i915_cur_delayinfo, 0},
> {"i915_delayfreq_table", i915_delayfreq_table, 0},
> @@ -1951,6 +2009,12 @@ int i915_debugfs_init(struct drm_minor *minor)
> if (ret)
> return ret;
>
> + ret = i915_debugfs_create(minor->debugfs_root, minor,
> + "i915_error_state",
> + &i915_error_state_fops);
> + if (ret)
> + return ret;
> +
> return drm_debugfs_create_files(i915_debugfs_list,
> I915_DEBUGFS_ENTRIES,
> minor->debugfs_root, minor);
> --
> 1.7.9
>
--
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48
