Commit 07144428 authored by Damien Lespiau's avatar Damien Lespiau Committed by Daniel Vetter

drm/i915: Implement blocking read for pipe CRC files

seq_file is not quite the right interface for these ones. We have a
circular buffer with a new entry per vblank on one side and a process
wanting to dequeue the CRC with a read().

It's quite racy to wait for vblank in user land and then try to read a
pipe_crc file, sometimes the CRC interrupt hasn't been fired and we end
up with an EOF.

So, let's have the read on the pipe_crc file block until the interrupt
gives us a new entry. At that point we can wake the reading process.
Signed-off-by: default avatarDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 497666d8
......@@ -1760,37 +1760,138 @@ static int i915_pc8_status(struct seq_file *m, void *unused)
return 0;
}
static int i915_pipe_crc(struct seq_file *m, void *data)
struct pipe_crc_info {
const char *name;
struct drm_device *dev;
enum pipe pipe;
};
static int i915_pipe_crc_open(struct inode *inode, struct file *filep)
{
filep->private_data = inode->i_private;
return 0;
}
static int i915_pipe_crc_release(struct inode *inode, struct file *filep)
{
return 0;
}
/* (6 fields, 8 chars each, space separated (5) + '\n') */
#define PIPE_CRC_LINE_LEN (6 * 8 + 5 + 1)
/* account for \'0' */
#define PIPE_CRC_BUFFER_LEN (PIPE_CRC_LINE_LEN + 1)
static int pipe_crc_data_count(struct intel_pipe_crc *pipe_crc)
{
struct drm_info_node *node = (struct drm_info_node *) m->private;
struct drm_device *dev = node->minor->dev;
struct drm_i915_private *dev_priv = dev->dev_private;
enum pipe pipe = (enum pipe)node->info_ent->data;
struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
int head, tail;
if (dev_priv->pipe_crc[pipe].source == INTEL_PIPE_CRC_SOURCE_NONE) {
seq_puts(m, "none\n");
head = atomic_read(&pipe_crc->head);
tail = atomic_read(&pipe_crc->tail);
return CIRC_CNT(head, tail, INTEL_PIPE_CRC_ENTRIES_NR);
}
static ssize_t
i915_pipe_crc_read(struct file *filep, char __user *user_buf, size_t count,
loff_t *pos)
{
struct pipe_crc_info *info = filep->private_data;
struct drm_device *dev = info->dev;
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[info->pipe];
char buf[PIPE_CRC_BUFFER_LEN];
int head, tail, n_entries, n;
ssize_t bytes_read;
/*
* Don't allow user space to provide buffers not big enough to hold
* a line of data.
*/
if (count < PIPE_CRC_LINE_LEN)
return -EINVAL;
if (pipe_crc->source == INTEL_PIPE_CRC_SOURCE_NONE)
return 0;
/* nothing to read */
while (pipe_crc_data_count(pipe_crc) == 0) {
if (filep->f_flags & O_NONBLOCK)
return -EAGAIN;
if (wait_event_interruptible(pipe_crc->wq,
pipe_crc_data_count(pipe_crc)))
return -ERESTARTSYS;
}
seq_puts(m, " frame CRC1 CRC2 CRC3 CRC4 CRC5\n");
/* We now have one or more entries to read */
head = atomic_read(&pipe_crc->head);
tail = atomic_read(&pipe_crc->tail);
while (CIRC_CNT(head, tail, INTEL_PIPE_CRC_ENTRIES_NR) >= 1) {
n_entries = min((size_t)CIRC_CNT(head, tail, INTEL_PIPE_CRC_ENTRIES_NR),
count / PIPE_CRC_LINE_LEN);
bytes_read = 0;
n = 0;
do {
struct intel_pipe_crc_entry *entry = &pipe_crc->entries[tail];
int ret;
seq_printf(m, "%8u %8x %8x %8x %8x %8x\n", entry->frame,
entry->crc[0], entry->crc[1], entry->crc[2],
entry->crc[3], entry->crc[4]);
bytes_read += snprintf(buf, PIPE_CRC_BUFFER_LEN,
"%8u %8x %8x %8x %8x %8x\n",
entry->frame, entry->crc[0],
entry->crc[1], entry->crc[2],
entry->crc[3], entry->crc[4]);
ret = copy_to_user(user_buf + n * PIPE_CRC_LINE_LEN,
buf, PIPE_CRC_LINE_LEN);
if (ret == PIPE_CRC_LINE_LEN)
return -EFAULT;
BUILD_BUG_ON_NOT_POWER_OF_2(INTEL_PIPE_CRC_ENTRIES_NR);
tail = (tail + 1) & (INTEL_PIPE_CRC_ENTRIES_NR - 1);
atomic_set(&pipe_crc->tail, tail);
}
n++;
} while (--n_entries);
return 0;
return bytes_read;
}
static const struct file_operations i915_pipe_crc_fops = {
.owner = THIS_MODULE,
.open = i915_pipe_crc_open,
.read = i915_pipe_crc_read,
.release = i915_pipe_crc_release,
};
static struct pipe_crc_info i915_pipe_crc_data[I915_MAX_PIPES] = {
{
.name = "i915_pipe_A_crc",
.pipe = PIPE_A,
},
{
.name = "i915_pipe_B_crc",
.pipe = PIPE_B,
},
{
.name = "i915_pipe_C_crc",
.pipe = PIPE_C,
},
};
static int i915_pipe_crc_create(struct dentry *root, struct drm_minor *minor,
enum pipe pipe)
{
struct drm_device *dev = minor->dev;
struct dentry *ent;
struct pipe_crc_info *info = &i915_pipe_crc_data[pipe];
info->dev = dev;
ent = debugfs_create_file(info->name, S_IRUGO, root, info,
&i915_pipe_crc_fops);
if (IS_ERR(ent))
return PTR_ERR(ent);
return drm_add_fake_info_node(minor, ent, info);
}
static const char *pipe_crc_sources[] = {
......@@ -2555,9 +2656,6 @@ static struct drm_info_list i915_debugfs_list[] = {
{"i915_edp_psr_status", i915_edp_psr_status, 0},
{"i915_energy_uJ", i915_energy_uJ, 0},
{"i915_pc8_status", i915_pc8_status, 0},
{"i915_pipe_A_crc", i915_pipe_crc, 0, (void *)PIPE_A},
{"i915_pipe_B_crc", i915_pipe_crc, 0, (void *)PIPE_B},
{"i915_pipe_C_crc", i915_pipe_crc, 0, (void *)PIPE_C},
};
#define I915_DEBUGFS_ENTRIES ARRAY_SIZE(i915_debugfs_list)
......@@ -2578,6 +2676,18 @@ static struct i915_debugfs_files {
{"i915_display_crc_ctl", &i915_display_crc_ctl_fops},
};
void intel_display_crc_init(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
int i;
for (i = 0; i < INTEL_INFO(dev)->num_pipes; i++) {
struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[i];
init_waitqueue_head(&pipe_crc->wq);
}
}
int i915_debugfs_init(struct drm_minor *minor)
{
int ret, i;
......@@ -2586,6 +2696,12 @@ int i915_debugfs_init(struct drm_minor *minor)
if (ret)
return ret;
for (i = 0; i < ARRAY_SIZE(i915_pipe_crc_data); i++) {
ret = i915_pipe_crc_create(minor->debugfs_root, minor, i);
if (ret)
return ret;
}
for (i = 0; i < ARRAY_SIZE(i915_debugfs_files); i++) {
ret = i915_debugfs_create(minor->debugfs_root, minor,
i915_debugfs_files[i].name,
......@@ -2601,12 +2717,22 @@ int i915_debugfs_init(struct drm_minor *minor)
void i915_debugfs_cleanup(struct drm_minor *minor)
{
struct drm_device *dev = minor->dev;
int i;
drm_debugfs_remove_files(i915_debugfs_list,
I915_DEBUGFS_ENTRIES, minor);
drm_debugfs_remove_files((struct drm_info_list *) &i915_forcewake_fops,
1, minor);
for (i = 0; i < INTEL_INFO(dev)->num_pipes; i++) {
struct drm_info_list *info_list =
(struct drm_info_list *)&i915_pipe_crc_data[i];
drm_debugfs_remove_files(info_list, 1, minor);
}
for (i = 0; i < ARRAY_SIZE(i915_debugfs_files); i++) {
struct drm_info_list *info_list =
(struct drm_info_list *) i915_debugfs_files[i].fops;
......
......@@ -1514,6 +1514,8 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
dev_priv->pc8.disable_count = 2; /* requirements_met + gpu_idle */
INIT_DELAYED_WORK(&dev_priv->pc8.enable_work, hsw_enable_pc8_work);
intel_display_crc_init(dev);
i915_dump_device_info(dev_priv);
/* Not all pre-production machines fall into this category, only the
......
......@@ -1235,6 +1235,7 @@ struct intel_pipe_crc {
struct intel_pipe_crc_entry *entries;
enum intel_pipe_crc_source source;
atomic_t head, tail;
wait_queue_head_t wq;
};
typedef struct drm_i915_private {
......@@ -2233,6 +2234,11 @@ int i915_verify_lists(struct drm_device *dev);
/* i915_debugfs.c */
int i915_debugfs_init(struct drm_minor *minor);
void i915_debugfs_cleanup(struct drm_minor *minor);
#if defined(CONFIG_DEBUG_FS)
void intel_display_crc_init(struct drm_device *dev);
#else
void intel_display_crc_init(struct drm_device *dev) {}
#endif
/* i915_gpu_error.c */
__printf(2, 3)
......
......@@ -1221,6 +1221,8 @@ static void ivb_pipe_crc_update(struct drm_device *dev, enum pipe pipe)
head = (head + 1) & (INTEL_PIPE_CRC_ENTRIES_NR - 1);
atomic_set(&pipe_crc->head, head);
wake_up_interruptible(&pipe_crc->wq);
}
#else
static void ivb_pipe_crc_update(struct drm_device *dev, int pipe) {}
......
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