[ivtv-devel] [PATCH] cx25840 i2c cleanup

[Bryan Mayland]

This patch prevents us from probing other i2c adapters for cx25840 
chips, which is a problem Chris Baumgartner identified.  I also added 
code to not return a bogus value from cx25840_read if the read fails (it 
now returns 0 on failure).
Index: driver/cx25840-driver.c
===================================================================
--- driver/cx25840-driver.c     (revision 313)
+++ driver/cx25840-driver.c     (working copy)
@@ -126,8 +126,13 @@
        u8 buffer[2];
        buffer[0] = addr >> 8;
        buffer[1] = addr & 0xff;
-       i2c_master_send(client, buffer, 2);
-       i2c_master_recv(client, buffer, 1);
+
+       if (i2c_master_send(client, buffer, 2) < 2)
+               return 0;
+
+       if (i2c_master_recv(client, buffer, 1) < 1)
+               return 0;
+
        return buffer[0];
 }
 
@@ -1027,7 +1032,7 @@
                kfree(client);
                return 0;
        }
-       DEBUG(1, "cx25%3x-2%x found", 
+       DEBUG(1, "cx25%3x-2%x found. Initializing...", 
                (device_id & 0xfff0) >> 4,
                (device_id & 0x0f) < 3 ? (device_id & 0x0f) + 1 : 3);
 
@@ -1049,8 +1054,6 @@
        state->audio = DECODER_AUDIO_48_KHZ;
        state->audio_input = -1;
 
-       DEBUG(1, "writing init values");
-
        switch (cardtype) {
        case 0:
                cx25840_input_layout = pvr150_input_layout;
@@ -1065,7 +1068,6 @@
 
        cx25840_initialize(client);
 
-
        i2c_attach_client(client);
        log_status(client);
        return 0;
@@ -1073,9 +1075,11 @@
 
 static int cx25840_attach_adapter(struct i2c_adapter *adapter)
 {
-       DEBUG(1, "starting probe for adapter %s (0x%x)", adapter->name,
-             adapter->id);
-       return i2c_probe(adapter, &addr_data, &cx25840_detect_client);
+       if (adapter->id == (I2C_ALGO_BIT | I2C_HW_B_BT848)) {
+               DEBUG(1, "starting probe for adapter %s (0x%x)", adapter->name,
+                       adapter->id);
+               return i2c_probe(adapter, &addr_data, &cx25840_detect_client);
+       }
        return 0;
 }