From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 32CF143D4E3; Mon, 20 Apr 2026 13:29:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776691797; cv=none; b=j52rI1q63vm+oi8Ckt41z/QZuQCp+y4PqZyEm1DMzfIxx91spU1Rw1f4gYbsHiuZ0kzXY8B9oeAGIHXNdxUtrtzg41rtB+SdJxRlNFjocZu/EtEO6dmemlmIDHqs09AdoOY9Wy3oMZxZSzyzcFEaqrNvQ0sW3bWC7SWMBUlSDKg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776691797; c=relaxed/simple; bh=bayKu25Lw6g0OLNSh41kpkBBpdp1Kk40gGr80cFvE40=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dU5JEFWO7eutm8OlVqnsqGwoS7PD67wEDeQd3T0NneeGlEKU6jPONFxFGRIvZe5v1HHVfABF8ywixMoqIXaIdgZRUFl5O9yNEOdfNKaswkwpgAYZLAaVbXvYFcUgkZKl2Bl40GCRioFSjDYHelz2BR6UFtVYCxjShF1ZGgY07os= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=i1ymmVcf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="i1ymmVcf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 734D6C19425; Mon, 20 Apr 2026 13:29:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776691797; bh=bayKu25Lw6g0OLNSh41kpkBBpdp1Kk40gGr80cFvE40=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i1ymmVcfK6DsJyd2NT2eaJmaUgeOCxJEp9TnJBFLdJsKhBqOcghcUl90aDDUAaZUx Ba2VaNU3VYKuH5V79a6gMLtH5Ev3QZ5VYzNywkJR+j8J6Z22J+4/9HztE6gSxPLIQ1 8+x/0d110G85DBZR6nNpQKC193Cg7QkCbw036NyMluxQSSmTUnzGNY7GX073Yg0KZH 399HFKzMBBbrDGzBWh1dHocgx2q4ABT8E83k0xzUYCfmT81+8PwQcuxUnrp6lucD7n btdjdH/9hSenVzp1ntDvWqleU5Xn3luRJZOsWaLDFOOOw+5u2GTzGl/ILk+7WGG8KO ZAPOt94XusK8g== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Tomasz Merta , Tomasz Merta , Mark Brown , Sasha Levin , olivier.moysan@foss.st.com, arnaud.pouliquen@foss.st.com, lgirdwood@gmail.com, perex@perex.cz, tiwai@suse.com, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, linux-sound@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH AUTOSEL 6.18] ASoC: stm32_sai: fix incorrect BCLK polarity for DSP_A/B, LEFT_J Date: Mon, 20 Apr 2026 09:19:53 -0400 Message-ID: <20260420132314.1023554-199-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260420132314.1023554-1-sashal@kernel.org> References: <20260420132314.1023554-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.18.23 Content-Transfer-Encoding: 8bit From: Tomasz Merta [ Upstream commit 0669631dbccd41cf3ca7aa70213fcd8bb41c4b38 ] The STM32 SAI driver do not set the clock strobing bit (CKSTR) for DSP_A, DSP_B and LEFT_J formats, causing data to be sampled on the wrong BCLK edge when SND_SOC_DAIFMT_NB_NF is used. Per ALSA convention, NB_NF requires sampling on the rising BCLK edge. The STM32MP25 SAI reference manual states that CKSTR=1 is required for signals received by the SAI to be sampled on the SCK rising edge. Without setting CKSTR=1, the SAI samples on the falling edge, violating the NB_NF convention. For comparison, the NXP FSL SAI driver correctly sets FSL_SAI_CR2_BCP for DSP_A, DSP_B and LEFT_J, consistent with its I2S handling. This patch adds SAI_XCR1_CKSTR for DSP_A, DSP_B and LEFT_J in stm32_sai_set_dai_fmt which was verified empirically with a cs47l35 codec. RIGHT_J (LSB) is not investigated and addressed by this patch. Note: the STM32 I2S driver (stm32_i2s_set_dai_fmt) may have the same issue for DSP_A mode, as I2S_CGFR_CKPOL is not set. This has not been verified and is left for a separate investigation. Signed-off-by: Tomasz Merta Link: https://patch.msgid.link/20260408084056.20588-1-tommerta@gmail.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- LLM Generated explanations, may be completely bogus: Error: Failed to generate final synthesis sound/soc/stm/stm32_sai_sub.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/sound/soc/stm/stm32_sai_sub.c b/sound/soc/stm/stm32_sai_sub.c index 5ae4d2577f28b..c2540383ab86f 100644 --- a/sound/soc/stm/stm32_sai_sub.c +++ b/sound/soc/stm/stm32_sai_sub.c @@ -802,6 +802,7 @@ static int stm32_sai_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt) break; /* Left justified */ case SND_SOC_DAIFMT_MSB: + cr1 |= SAI_XCR1_CKSTR; frcr |= SAI_XFRCR_FSPOL | SAI_XFRCR_FSDEF; break; /* Right justified */ @@ -809,9 +810,11 @@ static int stm32_sai_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt) frcr |= SAI_XFRCR_FSPOL | SAI_XFRCR_FSDEF; break; case SND_SOC_DAIFMT_DSP_A: + cr1 |= SAI_XCR1_CKSTR; frcr |= SAI_XFRCR_FSPOL | SAI_XFRCR_FSOFF; break; case SND_SOC_DAIFMT_DSP_B: + cr1 |= SAI_XCR1_CKSTR; frcr |= SAI_XFRCR_FSPOL; break; default: -- 2.53.0