On Tue, 13 Nov 2012 15:48:28 +0200, Mika Kuoppala <mika.kuoppala at linux.intel.com> wrote:
> 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.
>
> Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 83 +++++++++++++++++++++++++++++++++++
> 1 file changed, 83 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 4568e7d..8da4f55 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -839,6 +839,83 @@ 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;
> +
> + len = snprintf(buf, sizeof(buf),
> + "next_seqno : 0x%x\n",
> + dev_priv->next_seqno);
Probably worth the overhead of taking the mutex here for consistency.
Saves actual having to think in future.
> +
> + 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 (val > dev_priv->next_seqno) {
i915_seqno_passed() ?
> + dev_priv->next_seqno = val;
> + ret = 0;
redundant
> + DRM_DEBUG_DRIVER("Advancing seqno to %u\n", val);
> + } else {
> + ret = -EINVAL;
> + }
> +
> + mutex_unlock(&dev->struct_mutex);
> +
> + if (ret)
> + return ret;
> +
> + return cnt;
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;
> @@ -2103,6 +2180,12 @@ 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;
We really need to start cleaning up these files along an error path...
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
