Commit eea8f024 authored by Bjorn Andersson's avatar Bjorn Andersson Committed by Rob Clark
Browse files

drm/msm/dp: Simplify the dp_debug debugfs show function 



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.

Reviewed-by: default avatarStephen Boyd <swboyd@chromium.org>
Signed-off-by: default avatarBjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211007190211.3158868-1-bjorn.andersson@linaro.org


Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
parent 899b2608

drivers/gpu/drm/msm/dp/dp_debug.c

+25 −138
Original line number Diff line number Diff line
@@ -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;

	const 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)

{
@@ -306,11 +198,6 @@ 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,