FAILED: patch "[PATCH] ALSA: hda/ext: preserve PPLCCTL bits when clearing reset" failed to apply to 6.1-stable tree

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 36aa66de481d29edd63cbad9b5c4dc18c340fdf6
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026090344-passenger-submersed-9dfe@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 36aa66de481d29edd63cbad9b5c4dc18c340fdf6 Mon Sep 17 00:00:00 2001
From: Xu Rao <[email protected]>
Date: Thu, 13 Aug 2026 14:55:24 +0800
Subject: [PATCH] ALSA: hda/ext: preserve PPLCCTL bits when clearing reset

snd_hdac_ext_stream_reset() polls PPLCCTL for STRST by masking the register value with AZX_PPLCCTL_STRST:

	val = readl(...) & AZX_PPLCCTL_STRST;

The same masked value is then used when clearing STRST. Since val contains no bits other than STRST, clearing STRST from it always produces zero. The subsequent writel() therefore writes zero to the entire PPLCCTL register instead of clearing only the reset bit.

PPLCCTL contains other stream control fields, including the stream tag in AZX_PPLCCTL_STRM_MASK. Those fields must not be modified as a side effect of clearing stream reset.

Use snd_hdac_updatel() to clear STRST, matching the existing set-reset path and preserving all unrelated PPLCCTL bits.

index 4c7506d49f55..517bd151fcc3 100644
@@ -210,8 +210,8 @@ void snd_hdac_ext_stream_reset(struct hdac_ext_stream *hext_stream)
 			break;
 		udelay(3);
 	} while (--timeout);
-	val &= ~AZX_PPLCCTL_STRST;
-	writel(val, hext_stream->pplc_addr + AZX_REG_PPLCCTL);
+	snd_hdac_updatel(hext_stream->pplc_addr, AZX_REG_PPLCCTL,
+			 AZX_PPLCCTL_STRST, 0);
 	udelay(3);
 
 	timeout = 50;

From: Xu Rao <[email protected]>

[ Upstream commit 36aa66de481d29edd63cbad9b5c4dc18c340fdf6 ]

snd_hdac_ext_stream_reset() polls PPLCCTL for STRST by masking the register value with AZX_PPLCCTL_STRST:

	val = readl(...) & AZX_PPLCCTL_STRST;

The same masked value is then used when clearing STRST. Since val contains no bits other than STRST, clearing STRST from it always produces zero. The subsequent writel() therefore writes zero to the entire PPLCCTL register instead of clearing only the reset bit.

PPLCCTL contains other stream control fields, including the stream tag in AZX_PPLCCTL_STRM_MASK. Those fields must not be modified as a side effect of clearing stream reset.

Use snd_hdac_updatel() to clear STRST, matching the existing set-reset path and preserving all unrelated PPLCCTL bits.

---
 sound/hda/ext/hdac_ext_stream.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

index 70f3ad71aaf0d..4681d25a38448 100644
@@ -182,8 +182,8 @@ void snd_hdac_ext_link_stream_reset(struct hdac_ext_stream *hext_stream)
 			break;
 		udelay(3);
 	} while (--timeout);
-	val &= ~AZX_PPLCCTL_STRST;
-	writel(val, hext_stream->pplc_addr + AZX_REG_PPLCCTL);
+	snd_hdac_updatel(hext_stream->pplc_addr, AZX_REG_PPLCCTL,
+			 AZX_PPLCCTL_STRST, 0);
 	udelay(3);
 
 	timeout = 50;

2.53.0