[media] lirc_zilog: z8 on usb doesn't like back-to-back i2c_master_send
Both the HD-PVR and HVR-1950, driven by the hdpvr and pvrusb2 drivers
respectively, have a zilog z8 chip exposed via i2c. These are both
usb-connected devices, and on both of them, back-to-back i2c_master_send
calls that work fine with a z8 on a pci card fail with a -EIO, as the
chip isn't yet ready from the prior command. To cope with that, add a
delay and retry loop where necessary.
Acked-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/staging/lirc/lirc_zilog.c b/drivers/staging/lirc/lirc_zilog.c
index 3fe5f41..0aad0d7 100644
--- a/drivers/staging/lirc/lirc_zilog.c
+++ b/drivers/staging/lirc/lirc_zilog.c
@@ -495,7 +495,7 @@
/* send boot data to the IR TX device */
static int send_boot_data(struct IR_tx *tx)
{
- int ret;
+ int ret, i;
unsigned char buf[4];
/* send the boot block */
@@ -503,7 +503,7 @@
if (ret != 0)
return ret;
- /* kick it off? */
+ /* Hit the go button to activate the new boot data */
buf[0] = 0x00;
buf[1] = 0x20;
ret = i2c_master_send(tx->c, buf, 2);
@@ -511,7 +511,19 @@
zilog_error("i2c_master_send failed with %d\n", ret);
return ret < 0 ? ret : -EFAULT;
}
- ret = i2c_master_send(tx->c, buf, 1);
+
+ /*
+ * Wait for zilog to settle after hitting go post boot block upload.
+ * Without this delay, the HD-PVR and HVR-1950 both return an -EIO
+ * upon attempting to get firmware revision, and tx probe thus fails.
+ */
+ for (i = 0; i < 10; i++) {
+ ret = i2c_master_send(tx->c, buf, 1);
+ if (ret == 1)
+ break;
+ udelay(100);
+ }
+
if (ret != 1) {
zilog_error("i2c_master_send failed with %d\n", ret);
return ret < 0 ? ret : -EFAULT;
@@ -523,8 +535,8 @@
zilog_error("i2c_master_recv failed with %d\n", ret);
return 0;
}
- if (buf[0] != 0x80) {
- zilog_error("unexpected IR TX response: %02x\n", buf[0]);
+ if ((buf[0] != 0x80) && (buf[0] != 0xa0)) {
+ zilog_error("unexpected IR TX init response: %02x\n", buf[0]);
return 0;
}
zilog_notify("Zilog/Hauppauge IR blaster firmware version "
@@ -827,7 +839,15 @@
zilog_error("i2c_master_send failed with %d\n", ret);
return ret < 0 ? ret : -EFAULT;
}
- ret = i2c_master_send(tx->c, buf, 1);
+
+ /* Give the z8 a moment to process data block */
+ for (i = 0; i < 10; i++) {
+ ret = i2c_master_send(tx->c, buf, 1);
+ if (ret == 1)
+ break;
+ udelay(100);
+ }
+
if (ret != 1) {
zilog_error("i2c_master_send failed with %d\n", ret);
return ret < 0 ? ret : -EFAULT;