V4L/DVB (7610): em28xx: Select reg wait time based on chip ID

This is more conservative than just removing the msleep() from
em28xx_write_regs_req(), since some old hardware may still need it.
So, it will remove the sleep time only for those chips where this
removal were tested.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

4 files changed, 20 insertions, 4 deletions

diff --git a/drivers/media/video/em28xx/em28xx-cards.c b/drivers/media/video/em28xx/em28xx-cards.c
index 7dfea3ac9b2f..0c71e599c140 100644
--- a/drivers/media/video/em28xx/em28xx-cards.c
+++ b/drivers/media/video/em28xx/em28xx-cards.c
@@ -525,6 +525,20 @@ static void em28xx_set_model(struct em28xx *dev)
  */
 void em28xx_pre_card_setup(struct em28xx *dev)
 {
+        int rc;
+
+        dev->wait_after_write = 5;
+        rc = em28xx_read_reg(dev, CHIPID_REG);
+        if (rc > 0) {
+                switch (rc) {
+                case 36:
+                        em28xx_info("chip ID is em2882/em2883\n");
+                        dev->wait_after_write = 0;
+                        break;
+                default:
+                        em28xx_info("em28xx chip ID = %d\n", rc);
+                }
+        }
         em28xx_set_model(dev);
 
         /* request some modules */
diff --git a/drivers/media/video/em28xx/em28xx-core.c b/drivers/media/video/em28xx/em28xx-core.c
index 9cbc4788090c..e47b206187b5 100644
--- a/drivers/media/video/em28xx/em28xx-core.c
+++ b/drivers/media/video/em28xx/em28xx-core.c
@@ -153,6 +153,9 @@ int em28xx_write_regs_req(struct em28xx *dev, u8 req, u16 reg, char *buf,
         ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), req,
                               USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                               0x0000, reg, bufs, len, HZ);
+        if (dev->wait_after_write)
+                msleep(dev->wait_after_write);
+
         kfree(bufs);
         return ret;
 }
diff --git a/drivers/media/video/em28xx/em28xx-video.c b/drivers/media/video/em28xx/em28xx-video.c
index 1ac90322d681..a8aa09c5bc5f 100644
--- a/drivers/media/video/em28xx/em28xx-video.c
+++ b/drivers/media/video/em28xx/em28xx-video.c
@@ -1927,10 +1927,6 @@ static int em28xx_init_dev(struct em28xx **devhandle, struct usb_device *udev,
         dev->em28xx_read_reg_req = em28xx_read_reg_req;
         dev->is_em2800 = em28xx_boards[dev->model].is_em2800;
 
-        errCode = em28xx_read_reg(dev, CHIPID_REG);
-        if (errCode >= 0)
-                em28xx_info("em28xx chip ID = %d\n", errCode);
-
         em28xx_pre_card_setup(dev);
 
         errCode = em28xx_config(dev);
diff --git a/drivers/media/video/em28xx/em28xx.h b/drivers/media/video/em28xx/em28xx.h
index 5b21efaf7844..8f12b848b1d1 100644
--- a/drivers/media/video/em28xx/em28xx.h
+++ b/drivers/media/video/em28xx/em28xx.h
@@ -331,6 +331,9 @@ struct em28xx {
         unsigned int max_range_640_480:1;
         unsigned int has_dvb:1;
 
+        /* Some older em28xx chips needs a waiting time after writing */
+        unsigned int wait_after_write;
+
         /* GPIO sequences for tuner callback */
         struct em28xx_reg_seq *analog_gpio, *digital_gpio;