drm/i915: Keep the CRC values into a circular buffer

There are a few good properties to a circular buffer, for instance it
has a number of entries (before we were always dumping the full buffer).

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Damien Lespiau 2013-10-15 18:55:29 +01:00 committed by Daniel Vetter
parent 926321d503
commit b2c88f5b1d
3 changed files with 29 additions and 14 deletions

View File

@ -27,6 +27,7 @@
*/
#include <linux/seq_file.h>
#include <linux/circ_buf.h>
#include <linux/ctype.h>
#include <linux/debugfs.h>
#include <linux/slab.h>
@ -1739,25 +1740,28 @@ static int i915_pipe_crc(struct seq_file *m, void *data)
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;
const struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
int i;
int start;
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");
return 0;
}
start = atomic_read(&pipe_crc->slot) + 1;
seq_puts(m, " timestamp CRC1 CRC2 CRC3 CRC4 CRC5\n");
for (i = 0; i < INTEL_PIPE_CRC_ENTRIES_NR; i++) {
const struct intel_pipe_crc_entry *entry =
&pipe_crc->entries[(start + i) %
INTEL_PIPE_CRC_ENTRIES_NR];
head = atomic_read(&pipe_crc->head);
tail = atomic_read(&pipe_crc->tail);
while (CIRC_CNT(head, tail, INTEL_PIPE_CRC_ENTRIES_NR) >= 1) {
struct intel_pipe_crc_entry *entry = &pipe_crc->entries[tail];
seq_printf(m, "%12u %8x %8x %8x %8x %8x\n", entry->timestamp,
entry->crc[0], entry->crc[1], entry->crc[2],
entry->crc[3], entry->crc[4]);
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);
}
return 0;

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@ -1230,11 +1230,11 @@ struct intel_pipe_crc_entry {
uint32_t crc[5];
};
#define INTEL_PIPE_CRC_ENTRIES_NR 200
#define INTEL_PIPE_CRC_ENTRIES_NR 128
struct intel_pipe_crc {
struct intel_pipe_crc_entry entries[INTEL_PIPE_CRC_ENTRIES_NR];
enum intel_pipe_crc_source source;
atomic_t slot;
atomic_t head, tail;
};
typedef struct drm_i915_private {

View File

@ -30,6 +30,7 @@
#include <linux/sysrq.h>
#include <linux/slab.h>
#include <linux/circ_buf.h>
#include <drm/drmP.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"
@ -1195,20 +1196,30 @@ static void ivb_pipe_crc_update(struct drm_device *dev, enum pipe pipe)
struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
struct intel_pipe_crc_entry *entry;
ktime_t now;
int ts, slot;
int ts, head, tail;
head = atomic_read(&pipe_crc->head);
tail = atomic_read(&pipe_crc->tail);
if (CIRC_SPACE(head, tail, INTEL_PIPE_CRC_ENTRIES_NR) < 1) {
DRM_ERROR("CRC buffer overflowing\n");
return;
}
entry = &pipe_crc->entries[head];
now = ktime_get();
ts = ktime_to_us(now);
slot = (atomic_read(&pipe_crc->slot) + 1) % INTEL_PIPE_CRC_ENTRIES_NR;
entry = &pipe_crc->entries[slot];
entry->timestamp = ts;
entry->crc[0] = I915_READ(PIPE_CRC_RES_1_IVB(pipe));
entry->crc[1] = I915_READ(PIPE_CRC_RES_2_IVB(pipe));
entry->crc[2] = I915_READ(PIPE_CRC_RES_3_IVB(pipe));
entry->crc[3] = I915_READ(PIPE_CRC_RES_4_IVB(pipe));
entry->crc[4] = I915_READ(PIPE_CRC_RES_5_IVB(pipe));
atomic_set(&dev_priv->pipe_crc[pipe].slot, slot);
head = (head + 1) & (INTEL_PIPE_CRC_ENTRIES_NR - 1);
atomic_set(&pipe_crc->head, head);
}
#else
static void ivb_pipe_crc_update(struct drm_device *dev, int pipe) {}