[coreboot-gerrit] [S] Change in coreboot[main]: device/azalia: Clear busy bit after failed verb command

[Martin L Roth (Code Review)]

Martin L Roth has submitted this change. ( https://review.coreboot.org/c/coreboot/+/83592?usp=email )

Change subject: device/azalia: Clear busy bit after failed verb command
......................................................................

device/azalia: Clear busy bit after failed verb command

The spec tells us to clear the busy bit manually after a timeout. Do
that and wait immediately, to detect further issues early.  Also fix
some related comments and prints: Failures shouldn't be debug messa-
ges.  And we are talking to the PIO interface of the controller, not
the codec. So this was never about the codec being ready.

Change-Id: I4b737f8259157c01bfcd9e6631cc15d39c653d06
Signed-off-by: Nico Huber 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/83592
Reviewed-by: Nicholas Sudsgaard 
Tested-by: build bot (Jenkins) 
---
M src/device/azalia_device.c
1 file changed, 13 insertions(+), 6 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Nicholas Sudsgaard: Looks good to me, approved

diff --git a/src/device/azalia_device.c b/src/device/azalia_device.c
index c167373..dadcda9 100644
--- a/src/device/azalia_device.c
+++ b/src/device/azalia_device.c
@@ -155,10 +155,8 @@
 }

/*
- * Wait 50usec for the codec to indicate it is ready.
- * No response would imply that the codec is non-operative.
+ * Wait 50usec for the controller to indicate it is ready.
  */
-
 static int wait_for_ready(u8 *base)
 {
    struct stopwatch sw;
@@ -179,7 +177,6 @@
  * Wait for the codec to indicate that it accepted the previous command.
  * No response would imply that the codec is non-operative.
  */
-
 static int wait_for_valid(u8 *base)
 {
    struct stopwatch sw;
@@ -206,6 +203,16 @@
    	udelay(1);
    }

+	/*
+	 * HDA spec 1.0a "3.4.3 Offset 68h: Immediate Command Status"
+	 * tells us to clear the busy bit explicitly, then poll until
+	 * the controller is ready.
+	 */
+	write32(base + HDA_ICII_REG, 0);
+	if (wait_for_ready(base) < 0) {
+		printk(BIOS_WARNING, "azalia_audio: controller is unresponsive.\n");
+		return -2;
+	}
    return -1;
 }

@@ -238,7 +245,7 @@
 static bool codec_is_operative(u8 *base, const int addr)
 {
    if (wait_for_ready(base) < 0) {
-		printk(BIOS_DEBUG, "azalia_audio: codec #%d not ready\n", addr);
+		printk(BIOS_WARNING, "azalia_audio: controller not ready\n");
    	return false;
    }

@@ -246,7 +253,7 @@
    write32(base + HDA_IC_REG, reg32);

if (wait_for_valid(base) < 0) {
-		printk(BIOS_DEBUG, "azalia_audio: codec #%d not valid\n", addr);
+		printk(BIOS_NOTICE, "azalia_audio: codec #%d doesn't respond\n", addr);
    	return false;
    }
    return true;