drm: Use vsnprintf extension %ph

Using the extension saves a bit of code.

Miscellanea:

o Neaten and simplify dump_dp_payload_table
o Removed trailing blank space from output

$ size drivers/gpu/drm/drm_dp_mst_topology.o.* drivers/gpu/drm/tinydrm/*.o*
   text	   data	    bss	    dec	    hex	filename
  25848	      0	     16	  25864	   6508	drivers/gpu/drm/drm_dp_mst_topology.o.new
  26091	      0	     16	  26107	   65fb	drivers/gpu/drm/drm_dp_mst_topology.o.old
   3362	      2	      0	   3364	    d24	drivers/gpu/drm/tinydrm/mipi-dbi.o.new
   3376	      2	      0	   3378	    d32	drivers/gpu/drm/tinydrm/mipi-dbi.o.old

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/a78a21b5f34947da65473a0b7326922cda51a3be.1496187315.git.joe@perches.com

1 files changed, 16 insertions, 35 deletions

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 222eb1a8549b..bfd237c15e76 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2836,16 +2836,15 @@ static void drm_dp_mst_dump_mstb(struct seq_file *m,
 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
                                   char *buf)
 {
-        int ret;
         int i;
-        for (i = 0; i < 4; i++) {
-                ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
-                if (ret != 16)
-                        break;
+
+        for (i = 0; i < 64; i += 16) {
+                if (drm_dp_dpcd_read(mgr->aux,
+                                     DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
+                                     &buf[i], 16) != 16)
+                        return false;
         }
-        if (i == 4)
-                return true;
-        return false;
+        return true;
 }
 
 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
@@ -2909,42 +2908,24 @@ void drm_dp_mst_dump_topology(struct seq_file *m,
         mutex_lock(&mgr->lock);
         if (mgr->mst_primary) {
                 u8 buf[64];
-                bool bret;
                 int ret;
+
                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
-                seq_printf(m, "dpcd: ");
-                for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
-                        seq_printf(m, "%02x ", buf[i]);
-                seq_printf(m, "\n");
+                seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
                 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
-                seq_printf(m, "faux/mst: ");
-                for (i = 0; i < 2; i++)
-                        seq_printf(m, "%02x ", buf[i]);
-                seq_printf(m, "\n");
+                seq_printf(m, "faux/mst: %*ph\n", 2, buf);
                 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
-                seq_printf(m, "mst ctrl: ");
-                for (i = 0; i < 1; i++)
-                        seq_printf(m, "%02x ", buf[i]);
-                seq_printf(m, "\n");
+                seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
 
                 /* dump the standard OUI branch header */
                 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
-                seq_printf(m, "branch oui: ");
-                for (i = 0; i < 0x3; i++)
-                        seq_printf(m, "%02x", buf[i]);
-                seq_printf(m, " devid: ");
+                seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
                 for (i = 0x3; i < 0x8 && buf[i]; i++)
                         seq_printf(m, "%c", buf[i]);
-
-                seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
-                seq_printf(m, "\n");
-                bret = dump_dp_payload_table(mgr, buf);
-                if (bret == true) {
-                        seq_printf(m, "payload table: ");
-                        for (i = 0; i < 63; i++)
-                                seq_printf(m, "%02x ", buf[i]);
-                        seq_printf(m, "\n");
-                }
+                seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
+                           buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
+                if (dump_dp_payload_table(mgr, buf))
+                        seq_printf(m, "payload table: %*ph\n", 63, buf);
 
         }