From 0e7830b50b20fcc25f21f79b7734102284d7c8f9 Mon Sep 17 00:00:00 2001
From: Mauro Carvalho Chehab <mchehab@infradead.org>
Date: Sat, 14 Jun 2008 11:27:34 -0300
Subject: V4L/DVB (8029): Improve error message at tda1004x_attach

When an error occurs at firmware loading, sometimes, tda1004x stops answering.
Instead of reporting such error, attach code were assuming that the device were
answering an invalid ID (0xff). This can be seen when enabling debug options:

tda1004x: tda1004x_read_byte: reg=0x0
tda1004x: tda1004x_read_byte: error reg=0x0, ret=-5

Now, instead of reporting an invalid ID, it will report the correct error:

tda10046: chip is not answering. Giving up.
saa7133[0]/dvb: failed to attach tda10046
saa7133[0]/dvb: frontend initialization failed

A possible improvement would be trying to reset the device.

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

diff --git a/drivers/media/dvb/frontends/tda1004x.c b/drivers/media/dvb/frontends/tda1004x.c
index 3993d1c..a0d6386 100644
--- a/drivers/media/dvb/frontends/tda1004x.c
+++ b/drivers/media/dvb/frontends/tda1004x.c
@@ -1248,7 +1248,7 @@ struct dvb_frontend* tda10045_attach(const struct tda1004x_config* config,
 				     struct i2c_adapter* i2c)
 {
 	struct tda1004x_state *state;
-	u8 id;
+	int id;
 
 	/* allocate memory for the internal state */
 	state = kmalloc(sizeof(struct tda1004x_state), GFP_KERNEL);
@@ -1264,6 +1264,12 @@ struct dvb_frontend* tda10045_attach(const struct tda1004x_config* config,
 
 	/* check if the demod is there */
 	id = tda1004x_read_byte(state, TDA1004X_CHIPID);
+	if (id < 0) {
+		printk(KERN_ERR "tda10045: chip is not answering. Giving up.\n");
+		kfree(state);
+		return NULL;
+	}
+
 	if (id != 0x25) {
 		printk(KERN_ERR "Invalid tda1004x ID = 0x%02x. Can't proceed\n", id);
 		kfree(state);
@@ -1312,7 +1318,7 @@ struct dvb_frontend* tda10046_attach(const struct tda1004x_config* config,
 				     struct i2c_adapter* i2c)
 {
 	struct tda1004x_state *state;
-	u8 id;
+	int id;
 
 	/* allocate memory for the internal state */
 	state = kmalloc(sizeof(struct tda1004x_state), GFP_KERNEL);
@@ -1328,6 +1334,11 @@ struct dvb_frontend* tda10046_attach(const struct tda1004x_config* config,
 
 	/* check if the demod is there */
 	id = tda1004x_read_byte(state, TDA1004X_CHIPID);
+	if (id < 0) {
+		printk(KERN_ERR "tda10046: chip is not answering. Giving up.\n");
+		kfree(state);
+		return NULL;
+	}
 	if (id != 0x46) {
 		printk(KERN_ERR "Invalid tda1004x ID = 0x%02x. Can't proceed\n", id);
 		kfree(state);
-- 
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