From: Casey Tunturi via B4 Relay <devnull+casey.samaritansolutions.net@kernel.org>
To: Srinivas Kandagatla <srini@kernel.org>
Cc: linux-arm-msm@vger.kernel.org, linux-sound@vger.kernel.org,
linux-kernel@vger.kernel.org, phone-devel@vger.kernel.org,
stable@vger.kernel.org,
Casey Tunturi <casey@samaritansolutions.net>
Subject: [PATCH] slimbus: qcom-ngd-ctrl: match downstream DEF_ACT_CHAN encoding
Date: Fri, 07 Aug 2026 20:35:13 -0400 [thread overview]
Message-ID: <20260807-slimbus-def-act-chan-v1-1-fd542efb3d30@samaritansolutions.net> (raw)
From: Casey Tunturi <casey@samaritansolutions.net>
During my investigations, and some rather incessant cross-checking of
blueline's SLIMbus path, I found that Qualcomm's downstream driver
packs the first DEF_ACT_CHAN byte differently from mainline. Bits [7:5]
hold the data format; bits [4:0] hold the five-bit client number.
I changed ours to match. It made no immediate difference on my own
hardware: blueline's current values produce 0x0f either way. The
downstream layout is correct and should help devices that use upper
logical-address bits or a non-zero data format.
Fixes: 52490169cddf ("slimbus: ngd: add stream support")
Cc: stable@vger.kernel.org
Signed-off-by: Casey Tunturi <casey@samaritansolutions.net>
---
drivers/slimbus/qcom-ngd-ctrl.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/slimbus/qcom-ngd-ctrl.c b/drivers/slimbus/qcom-ngd-ctrl.c
index 3071e46d0..14192380d 100644
--- a/drivers/slimbus/qcom-ngd-ctrl.c
+++ b/drivers/slimbus/qcom-ngd-ctrl.c
@@ -1018,7 +1018,8 @@ static int qcom_slim_ngd_enable_stream(struct slim_stream_runtime *rt)
if (txn.msg->num_bytes == 0) {
int exp = 0, coef = 0;
- wbuf[txn.msg->num_bytes++] = sdev->laddr;
+ wbuf[txn.msg->num_bytes++] =
+ (port->ch.data_fmt << 5) | (sdev->laddr & 0x1f);
wbuf[txn.msg->num_bytes] = rt->bps >> 2 |
(port->ch.aux_fmt << 6);
---
base-commit: 55f2ea9ff83cc27a85526b14bc9b32f96a08d6ec
change-id: 20260807-slimbus-def-act-chan-b70e4fb7abb1
Best regards,
--
Casey Tunturi <casey@samaritansolutions.net>
next reply other threads:[~2026-08-08 0:35 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-08 0:35 Casey Tunturi via B4 Relay [this message]
2026-08-18 12:50 ` Konrad Dybcio
2026-09-17 22:26 ` Srinivas Kandagatla
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260807-slimbus-def-act-chan-v1-1-fd542efb3d30@samaritansolutions.net \
--to=devnull+casey.samaritansolutions.net@kernel.org \
--cc=casey@samaritansolutions.net \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sound@vger.kernel.org \
--cc=phone-devel@vger.kernel.org \
--cc=srini@kernel.org \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®