[media] solo6x10: Reduce OSD writes to the minimum necessary

Instead of unconditionally writing SOLO_EOSD_EXT_SIZE() bytes to the OSD
area (which is 64 or 128 kB depending on the PCI board) we only
write the actual amount of data needed which is 16 * OSD_TEXT_MAX (= 16 * 44).

Signed-off-by: Ismael Luceno <ismael.luceno@corp.bluecherry.net>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

2 files changed, 16 insertions, 17 deletions

diff --git a/drivers/staging/media/solo6x10/solo6x10-enc.c b/drivers/staging/media/solo6x10/solo6x10-enc.c
index 94d5735abf85..2db53b68c62f 100644
--- a/drivers/staging/media/solo6x10/solo6x10-enc.c
+++ b/drivers/staging/media/solo6x10/solo6x10-enc.c
@@ -134,51 +134,48 @@ static void solo_capture_config(struct solo_dev *solo_dev)
         kfree(buf);
 }
 
+#define SOLO_OSD_WRITE_SIZE (16 * OSD_TEXT_MAX)
+
 /* Should be called with enable_lock held */
 int solo_osd_print(struct solo_enc_dev *solo_enc)
 {
         struct solo_dev *solo_dev = solo_enc->solo_dev;
         unsigned char *str = solo_enc->osd_text;
         u8 *buf = solo_enc->osd_buf;
-        u32 reg = solo_reg_read(solo_dev, SOLO_VE_OSD_CH);
+        u32 reg;
         const struct font_desc *vga = find_font("VGA8x16");
         const unsigned char *vga_data;
-        int len;
         int i, j;
 
         if (WARN_ON_ONCE(!vga))
                 return -ENODEV;
 
-        len = strlen(str);
-
-        if (len == 0) {
+        reg = solo_reg_read(solo_dev, SOLO_VE_OSD_CH);
+        if (!*str) {
                 /* Disable OSD on this channel */
                 reg &= ~(1 << solo_enc->ch);
-                solo_reg_write(solo_dev, SOLO_VE_OSD_CH, reg);
-                return 0;
+                goto out;
         }
 
-        memset(buf, 0, SOLO_EOSD_EXT_SIZE_MAX);
+        memset(buf, 0, SOLO_OSD_WRITE_SIZE);
         vga_data = (const unsigned char *)vga->data;
 
-        for (i = 0; i < len; i++) {
-                unsigned char c = str[i];
-
+        for (i = 0; *str; i++, str++) {
                 for (j = 0; j < 16; j++) {
-                        buf[(j * 2) + (i % 2) + (i / 2 * 32)] =
-                                bitrev8(vga_data[(c * 16) + j]);
+                        buf[(j << 1) | (i & 1) | ((i & ~1) << 4)] =
+                            bitrev8(vga_data[(*str << 4) | j]);
                 }
         }
 
         solo_p2m_dma(solo_dev, 1, buf,
-                     SOLO_EOSD_EXT_ADDR +
-                     (solo_enc->ch * SOLO_EOSD_EXT_SIZE(solo_dev)),
-                     SOLO_EOSD_EXT_SIZE(solo_dev), 0, 0);
+                     SOLO_EOSD_EXT_ADDR_CHAN(solo_dev, solo_enc->ch),
+                     SOLO_OSD_WRITE_SIZE, 0, 0);
 
         /* Enable OSD on this channel */
         reg |= (1 << solo_enc->ch);
-        solo_reg_write(solo_dev, SOLO_VE_OSD_CH, reg);
 
+out:
+        solo_reg_write(solo_dev, SOLO_VE_OSD_CH, reg);
         return 0;
 }
 
diff --git a/drivers/staging/media/solo6x10/solo6x10-offsets.h b/drivers/staging/media/solo6x10/solo6x10-offsets.h
index f005dca501f1..13eeb4470dcf 100644
--- a/drivers/staging/media/solo6x10/solo6x10-offsets.h
+++ b/drivers/staging/media/solo6x10/solo6x10-offsets.h
@@ -35,6 +35,8 @@
 #define SOLO_EOSD_EXT_SIZE_MAX                  0x20000
 #define SOLO_EOSD_EXT_AREA(__solo) \
         (SOLO_EOSD_EXT_SIZE(__solo) * 32)
+#define SOLO_EOSD_EXT_ADDR_CHAN(__solo, ch) \
+        (SOLO_EOSD_EXT_ADDR + SOLO_EOSD_EXT_SIZE(__solo) * (ch))
 
 #define SOLO_MOTION_EXT_ADDR(__solo) \
         (SOLO_EOSD_EXT_ADDR + SOLO_EOSD_EXT_AREA(__solo))