The "dp_debug" show function allocates a buffer and piecemeal appends
line by line, checking for buffer overflows etc.
Migrate the function to seq_file, to remove all the extra book keeping
and simplify the function.
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---
drivers/gpu/drm/msm/dp/dp_debug.c | 161 +++++-------------------------
1 file changed, 24 insertions(+), 137 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_debug.c b/drivers/gpu/drm/msm/dp/dp_debug.c
index 2f6247e80e9d..566037942343 100644
--- a/drivers/gpu/drm/msm/dp/dp_debug.c
+++ b/drivers/gpu/drm/msm/dp/dp_debug.c
@@ -31,177 +31,69 @@ struct dp_debug_private {
struct dp_debug dp_debug;
};
-static int dp_debug_check_buffer_overflow(int rc, int *max_size, int *len)
+static int dp_debug_show(struct seq_file *seq, void *p)
{
- if (rc >= *max_size) {
- DRM_ERROR("buffer overflow\n");
- return -EINVAL;
- }
- *len += rc;
- *max_size = SZ_4K - *len;
-
- return 0;
-}
-
-static ssize_t dp_debug_read_info(struct file *file, char __user *user_buff,
- size_t count, loff_t *ppos)
-{
- struct dp_debug_private *debug = file->private_data;
- char *buf;
- u32 len = 0, rc = 0;
+ struct dp_debug_private *debug = seq->private;
u64 lclk = 0;
- u32 max_size = SZ_4K;
u32 link_params_rate;
struct drm_display_mode *drm_mode;
if (!debug)
return -ENODEV;
- if (*ppos)
- return 0;
-
- buf = kzalloc(SZ_4K, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
-
drm_mode = &debug->panel->dp_mode.drm_mode;
- rc = snprintf(buf + len, max_size, "\tname = %s\n", DEBUG_NAME);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\tdp_panel\n\t\tmax_pclk_khz = %d\n",
+ seq_printf(seq, "\tname = %s\n", DEBUG_NAME);
+ seq_printf(seq, "\tdp_panel\n\t\tmax_pclk_khz = %d\n",
debug->panel->max_pclk_khz);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\tdrm_dp_link\n\t\trate = %u\n",
+ seq_printf(seq, "\tdrm_dp_link\n\t\trate = %u\n",
debug->panel->link_info.rate);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\t\tnum_lanes = %u\n",
+ seq_printf(seq, "\t\tnum_lanes = %u\n",
debug->panel->link_info.num_lanes);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\t\tcapabilities = %lu\n",
+ seq_printf(seq, "\t\tcapabilities = %lu\n",
debug->panel->link_info.capabilities);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\tdp_panel_info:\n\t\tactive = %dx%d\n",
+ seq_printf(seq, "\tdp_panel_info:\n\t\tactive = %dx%d\n",
drm_mode->hdisplay,
drm_mode->vdisplay);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\t\tback_porch = %dx%d\n",
+ seq_printf(seq, "\t\tback_porch = %dx%d\n",
drm_mode->htotal - drm_mode->hsync_end,
drm_mode->vtotal - drm_mode->vsync_end);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\t\tfront_porch = %dx%d\n",
+ seq_printf(seq, "\t\tfront_porch = %dx%d\n",
drm_mode->hsync_start - drm_mode->hdisplay,
drm_mode->vsync_start - drm_mode->vdisplay);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\t\tsync_width = %dx%d\n",
+ seq_printf(seq, "\t\tsync_width = %dx%d\n",
drm_mode->hsync_end - drm_mode->hsync_start,
drm_mode->vsync_end - drm_mode->vsync_start);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\t\tactive_low = %dx%d\n",
+ seq_printf(seq, "\t\tactive_low = %dx%d\n",
debug->panel->dp_mode.h_active_low,
debug->panel->dp_mode.v_active_low);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\t\th_skew = %d\n",
+ seq_printf(seq, "\t\th_skew = %d\n",
drm_mode->hskew);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\t\trefresh rate = %d\n",
+ seq_printf(seq, "\t\trefresh rate = %d\n",
drm_mode_vrefresh(drm_mode));
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\t\tpixel clock khz = %d\n",
+ seq_printf(seq, "\t\tpixel clock khz = %d\n",
drm_mode->clock);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\t\tbpp = %d\n",
+ seq_printf(seq, "\t\tbpp = %d\n",
debug->panel->dp_mode.bpp);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
/* Link Information */
- rc = snprintf(buf + len, max_size,
- "\tdp_link:\n\t\ttest_requested = %d\n",
+ seq_printf(seq, "\tdp_link:\n\t\ttest_requested = %d\n",
debug->link->sink_request);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\t\tnum_lanes = %d\n",
+ seq_printf(seq, "\t\tnum_lanes = %d\n",
debug->link->link_params.num_lanes);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
link_params_rate = debug->link->link_params.rate;
- rc = snprintf(buf + len, max_size,
- "\t\tbw_code = %d\n",
+ seq_printf(seq, "\t\tbw_code = %d\n",
drm_dp_link_rate_to_bw_code(link_params_rate));
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
lclk = debug->link->link_params.rate * 1000;
- rc = snprintf(buf + len, max_size,
- "\t\tlclk = %lld\n", lclk);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\t\tv_level = %d\n",
+ seq_printf(seq, "\t\tlclk = %lld\n", lclk);
+ seq_printf(seq, "\t\tv_level = %d\n",
debug->link->phy_params.v_level);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- rc = snprintf(buf + len, max_size,
- "\t\tp_level = %d\n",
+ seq_printf(seq, "\t\tp_level = %d\n",
debug->link->phy_params.p_level);
- if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
- goto error;
-
- if (copy_to_user(user_buff, buf, len))
- goto error;
-
- *ppos += len;
- kfree(buf);
- return len;
- error:
- kfree(buf);
- return -EINVAL;
+ return 0;
}
+DEFINE_SHOW_ATTRIBUTE(dp_debug);
static int dp_test_data_show(struct seq_file *m, void *data)
{
@@ -349,11 +241,6 @@ static int dp_test_active_open(struct inode *inode,
inode->i_private);
}
-static const struct file_operations dp_debug_fops = {
- .open = simple_open,
- .read = dp_debug_read_info,
-};
-
static const struct file_operations test_active_fops = {
.owner = THIS_MODULE,
.open = dp_test_active_open,
--
2.29.2
