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@linaro.org --- 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,