From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794046310; b=WYfun7/AyDXK1m/yu6FlmrlUcsdGmBtQkK539kFIkYPOgvdX/eYU6+kA1+4/qaV3SWnh 0yBd06yia/VdpexUmwF4bVohFmy7iR9dsXpkXJx+0PkwVvaeOOnwgf++Tljd77u3wXQxQ grQ9F4L9udf416vJZzTmmhdSuqASG+TNMGJyFu+WL4J/xnjQJqvrH2plt5WEV0cSP/Zkc NBfR0BMNYZ4W8kA2/2piC9NEnItwRMPkXz/eDE5S1WAHxi32daixTnyzprjOvmmse6eL7 YboMPTvC0yn8SbD3zNJT6lR0oYIiRYWNP/g9y+eJnlLQuDvIlRXYmaGGoewv+rA0DXQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794046310; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=mu9FNT8WDN6dvZMEcR+nkvOAwLqDvUqsJkJFvP8hOk0=; b=OioshuymxImGNA2M+BGhkP0XreHk8iptgyWah66loa+hN3XZlgGqgzJVMwWLhy9V/VFA j3RpvkADCRZaOz1sCJU8e1usJxPCBGDdcJG3X25DDbtEfrKUHYKtM+pouNjvEpIynuY2l WNAj22I5kdb0/FnxsxaMZQ6pEzL4Nkks7jT00RnMvx9Gu3T/KWwIoQVv2AcGqHKx0/Leb fL79jJf4fUaJ3IQYKC9jCA9WYp8307z2ZW0/IjwpXe8BWATWNMY9sHVd7f1XqIFonINeW BebqPAkRbSg0lgegpRhQkqi2ZvoOWDQ0SY2Bux+htTekt1eexESJsFDG/R03dfTJhNA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Ts7p1uOk; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 10D10606A32C for ; Sat, 7 Nov 2026 10:11:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Ts7p1uOk Received: by smtp.kernel.org (Postfix) with ESMTPSA id BBDDB1F0089F; Sat, 7 Nov 2026 10:11:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794046309; bh=mu9FNT8WDN6dvZMEcR+nkvOAwLqDvUqsJkJFvP8hOk0=; h=From:To:Cc:Subject:Date; b=Ts7p1uOk3VHQMC+++ONXkQefOCLekljmS6k6ARf3BI87fIbPnT+07oZOnimNbl96N l7dr4xPr214KN5zmXFxzdB71IEuL5/w6KUKVCLvqA8KjZlx8OWHtdnjrwsDoi0T7zJ G08oElCf9bEy1SHDJtPNIepzqgixWQnewSJdzduhCecYi/DoVautlnhu46vBgv3yQH KszJy2lAK+NALNJe7u5+OvsIw4ikfQkp1PBw05ZVSqJfwn3+1BwTwdL/5fYsoMXBIa XtTQuoIgujsy02dGAk047g0t3FdHWw+7e5FauP1UIgv/LWXW8/w1IuA6r5OIE0yjtl yBqrGBNclu+IA== From: Sasha Levin To: tvlad744@gmail.com, srinivas.kandagatla@oss.qualcomm.com, broonie@kernel.org Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] ASoC: qcom: q6apm-dai: wrap the position of a full ring to 0" failed to apply to 6.18-stable tree Date: Sat, 7 Nov 2026 05:11:47 -0500 Message-ID: <20261107051147-failed-6.18-0ea3e0b196f9@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.18-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 . 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-6.18.y git checkout FETCH_HEAD git cherry-pick -x 0ea3e0b196f9dcc17b40ac881a6efef06459975b # git commit -s git send-email --to '' --in-reply-to '20261107051147-failed-6.18-0ea3e0b196f9@kernel.org' --subject-prefix 'PATCH 6.18.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 0ea3e0b196f9dcc17b40ac881a6efef06459975b Mon Sep 17 00:00:00 2001 From: Vladyslav Tymoshchuk Date: Wed, 14 Oct 2026 19:27:00 +0300 Subject: [PATCH] ASoC: qcom: q6apm-dai: wrap the position of a full ring to 0 q6apm_dai_pointer() turns the number of period buffers the DSP has returned in the current lap, 1..periods, into a position and reports one frame less than that. Commit a93dad6f4e6a ("ASoC: q6apm-dai: make use of q6apm_get_hw_pointer") added the "- 1" so that the end of the ring is not reported as a position equal to the buffer size. One frame short has a cost once the application stops feeding the stream. The DSP returns the last queued buffer and the position stops at appl_ptr - 1, so avail stays at buffer_size - 1, below the default stop_threshold. The DSP sends nothing more as its queue is empty, so no period interrupt comes either: ALSA never detects the underrun and the stream stays RUNNING. A poll-driven application that missed its last wakeup waits forever, and drain only ends on its timeout, with -EIO. On capture, the last frame of each period is held back until the next one. Before that commit the position wrapped to 0 at the end of the ring. Do that again. A full lap is the start of the ring, and snd_pcm_update_hw_ptr0() accounts for the wrap: the position cannot move by more than one lap between two updates, as each returned buffer calls snd_pcm_period_elapsed() and the DSP holds at most periods buffers. Seen on a OnePlus Pad 3 (SM8750) with PipeWire in interrupt-driven scheduling: after a stall the PCM sat at hw_ptr 78239, appl_ptr 78240 (avail 3839 of 3840) for two hours. Fixes: a93dad6f4e6a ("ASoC: q6apm-dai: make use of q6apm_get_hw_pointer") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-5-5 Signed-off-by: Vladyslav Tymoshchuk Reviewed-by: Srinivas Kandagatla Tested-by: Srinivas Kandagatla Link: https://patch.msgid.link/20261014162703.10172-2-tvlad744@gmail.com Signed-off-by: Mark Brown --- sound/soc/qcom/qdsp6/q6apm-dai.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/sound/soc/qcom/qdsp6/q6apm-dai.c b/sound/soc/qcom/qdsp6/q6apm-dai.c index b0b10ba51c99d..58beaf906b9ff 100644 --- a/sound/soc/qcom/qdsp6/q6apm-dai.c +++ b/sound/soc/qcom/qdsp6/q6apm-dai.c @@ -613,11 +613,15 @@ static snd_pcm_uframes_t q6apm_dai_pointer(struct snd_soc_component *component, ptr = bytes_to_frames(runtime, index); return ptr; } - ptr = q6apm_get_hw_pointer(prtd->graph, substream->stream) * runtime->period_size; - if (ptr) - return ptr - 1; + /* + * The hw pointer counts the period buffers the DSP has returned in + * this lap, 1..periods. A full lap is the start of the ring again: + * report 0 rather than one frame less, so that the position of a + * drained buffer reaches appl_ptr and ALSA sees the underrun. + */ + ptr = q6apm_get_hw_pointer(prtd->graph, substream->stream) % runtime->periods; - return 0; + return ptr * runtime->period_size; } static int q6apm_dai_hw_params(struct snd_soc_component *component, -- 2.53.0