V4L/DVB (9781): [PATCH] Cablestar 2 I2C retries (fix CableStar2 support)

At some point the Flexcop driver was changed to support newer Flexcop cards.
These modifications however broke the detection of Cablestar 2 DVB-C cards.

The reason is that the earlier version of the driver used to retry
unsuccessful i2c operations. The demodulator of Cablestar 2 cards (stv0297)
seems to be very dependent on these retries and adding them back fixes
Cablestar detection.

This patch restores this behaviour for the CableStar2.
Signed-off-by: Antti Seppälä <a.seppala@gmail.com>
Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/b2c2/flexcop-fe-tuner.c

@@ -628,12 +628,14 @@ int flexcop_frontend_init(struct flexcop_device *fc)
 	}
 
 	/* try the cable dvb (stv0297) */
+	fc->fc_i2c_adap[0].no_base_addr = 1;
 	fc->fe = dvb_attach(stv0297_attach, &alps_tdee4_stv0297_config, i2c);
 	if (fc->fe != NULL) {
 		fc->dev_type = FC_CABLE;
 		fc->fe->ops.tuner_ops.set_params = alps_tdee4_stv0297_tuner_set_params;
 		goto fe_found;
 	}
+	fc->fc_i2c_adap[0].no_base_addr = 0;
 
 	/* try the sky v2.3 (vp310/Samsung tbdu18132(tsa5059)) */
 	fc->fe = dvb_attach(mt312_attach,

drivers/media/dvb/b2c2/flexcop-i2c.c

@@ -47,8 +47,12 @@ static int flexcop_i2c_read4(struct flexcop_i2c_adapter *i2c,
 	int len = r100.tw_sm_c_100.total_bytes, /* remember total_bytes is buflen-1 */
 		ret;
 
-	r100.tw_sm_c_100.no_base_addr_ack_error = i2c->no_base_addr;
 	ret = flexcop_i2c_operation(i2c->fc, &r100);
+	if (ret != 0) {
+		deb_i2c("Retrying operation\n");
+		r100.tw_sm_c_100.no_base_addr_ack_error = i2c->no_base_addr;
+		ret = flexcop_i2c_operation(i2c->fc, &r100);
+	}
 	if (ret != 0) {
 		deb_i2c("read failed. %d\n", ret);
 		return ret;