Patrick Georgi has submitted this change. ( https://review.coreboot.org/c/coreboot/+/51634 )
Change subject: device/azalia_device.c: Unify `wait_for_valid` timeouts ......................................................................
device/azalia_device.c: Unify `wait_for_valid` timeouts
The timeout is never reached when the codec is functioning properly. Using a small timeout value can result in spurious errors with some codecs, e.g. a codec that is slow to respond but operates correctly. When a codec is non-operative, the timeout is only reached once per verb table, thus the impact on booting time is relatively small. So, use a reasonably long enough timeout to cover all possible cases.
Remove the unconditional 25 µs delay and increase the timeout delay. The new value of 1 ms is the maximum of all existing implementations. Currently, the only boards using this code are AMD reference boards: - AMD Bilby - AMD Mandolin - AMD Padmelon
Change-Id: Ia5e4829d404dcecdb9e7a377e896a319cb38531a Signed-off-by: Angel Pons th3fanbus@gmail.com Reviewed-on: https://review.coreboot.org/c/coreboot/+/51634 Tested-by: build bot (Jenkins) no-reply@coreboot.org Reviewed-by: Nico Huber nico.h@gmx.de --- M src/device/azalia_device.c 1 file changed, 11 insertions(+), 8 deletions(-)
Approvals: build bot (Jenkins): Verified Nico Huber: Looks good to me, approved
diff --git a/src/device/azalia_device.c b/src/device/azalia_device.c index 2787cb2..a0b8d5f 100644 --- a/src/device/azalia_device.c +++ b/src/device/azalia_device.c @@ -162,26 +162,29 @@ }
/* - * Wait 50usec for the codec to indicate that it accepted the previous command. - * No response would imply that the code is non-operative. + * 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; u32 reg32; - /* Use a 50 usec timeout - the Linux kernel uses the same duration */ - int timeout = 25;
/* Send the verb to the codec */ reg32 = read32(base + HDA_ICII_REG); reg32 |= HDA_ICII_BUSY | HDA_ICII_VALID; write32(base + HDA_ICII_REG, reg32);
- while (timeout--) - udelay(1); - - stopwatch_init_usecs_expire(&sw, 50); + /* + * The timeout is never reached when the codec is functioning properly. + * Using a small timeout value can result in spurious errors with some + * codecs, e.g. a codec that is slow to respond but operates correctly. + * When a codec is non-operative, the timeout is only reached once per + * verb table, thus the impact on booting time is relatively small. So, + * use a reasonably long enough timeout to cover all possible cases. + */ + stopwatch_init_msecs_expire(&sw, 1); while (!stopwatch_expired(&sw)) { reg32 = read32(base + HDA_ICII_REG); if ((reg32 & (HDA_ICII_VALID | HDA_ICII_BUSY)) == HDA_ICII_VALID)