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 9768C79C9 for ; Thu, 12 Jan 2023 14:32:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED8E5C433EF; Thu, 12 Jan 2023 14:32:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673533971; bh=Iu0ukPNx/nh1zgMZi1jsS1YZMig+iRHuKvcP16AKaBk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OI70PipElVF2K/+bFoqMt6X1o+65MZr5VoNg4yf/S/xXaS+ARQg0x2R83Gov9v2x8 UJng7H8HDdIxMHB/IaqdOKdhVb5FDHsDZFAyTh7T71Y02zTKvr1RWr6NaWZCSbU0TE Y/i9Tp8GHz8Z9XH50usuVeYYMdyAm/iXbXQrdrFw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paul Cercueil , Aidan MacDonald , Mark Brown Subject: [PATCH 5.10 652/783] ASoC: jz4740-i2s: Handle independent FIFO flush bits Date: Thu, 12 Jan 2023 14:56:08 +0100 Message-Id: <20230112135554.558427281@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230112135524.143670746@linuxfoundation.org> References: <20230112135524.143670746@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Aidan MacDonald commit 8b3a9ad86239f80ed569e23c3954a311f66481d6 upstream. On the JZ4740, there is a single bit that flushes (empties) both the transmit and receive FIFO. Later SoCs have independent flush bits for each FIFO. Independent FIFOs can be flushed before the snd_soc_dai_active() check because it won't disturb other active streams. This ensures that the FIFO we're about to use is always flushed before starting up. With shared FIFOs we can't do that because if another substream is active, flushing its FIFO would cause underrun errors. This also fixes a bug: since we were only setting the JZ4740's flush bit, which corresponds to the TX FIFO flush bit on other SoCs, other SoCs were not having their RX FIFO flushed at all. Fixes: 967beb2e8777 ("ASoC: jz4740: Add jz4780 support") Reviewed-by: Paul Cercueil Cc: stable@vger.kernel.org Signed-off-by: Aidan MacDonald Link: https://lore.kernel.org/r/20221023143328.160866-2-aidanmacdonald.0x0@gmail.com Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- sound/soc/jz4740/jz4740-i2s.c | 39 ++++++++++++++++++++++++++++++++++----- 1 file changed, 34 insertions(+), 5 deletions(-) --- a/sound/soc/jz4740/jz4740-i2s.c +++ b/sound/soc/jz4740/jz4740-i2s.c @@ -59,7 +59,8 @@ #define JZ_AIC_CTRL_MONO_TO_STEREO BIT(11) #define JZ_AIC_CTRL_SWITCH_ENDIANNESS BIT(10) #define JZ_AIC_CTRL_SIGNED_TO_UNSIGNED BIT(9) -#define JZ_AIC_CTRL_FLUSH BIT(8) +#define JZ_AIC_CTRL_TFLUSH BIT(8) +#define JZ_AIC_CTRL_RFLUSH BIT(7) #define JZ_AIC_CTRL_ENABLE_ROR_INT BIT(6) #define JZ_AIC_CTRL_ENABLE_TUR_INT BIT(5) #define JZ_AIC_CTRL_ENABLE_RFS_INT BIT(4) @@ -94,6 +95,8 @@ enum jz47xx_i2s_version { struct i2s_soc_info { enum jz47xx_i2s_version version; struct snd_soc_dai_driver *dai; + + bool shared_fifo_flush; }; struct jz4740_i2s { @@ -122,19 +125,44 @@ static inline void jz4740_i2s_write(cons writel(value, i2s->base + reg); } +static inline void jz4740_i2s_set_bits(const struct jz4740_i2s *i2s, + unsigned int reg, uint32_t bits) +{ + uint32_t value = jz4740_i2s_read(i2s, reg); + value |= bits; + jz4740_i2s_write(i2s, reg, value); +} + static int jz4740_i2s_startup(struct snd_pcm_substream *substream, struct snd_soc_dai *dai) { struct jz4740_i2s *i2s = snd_soc_dai_get_drvdata(dai); - uint32_t conf, ctrl; + uint32_t conf; int ret; + /* + * When we can flush FIFOs independently, only flush the FIFO + * that is starting up. We can do this when the DAI is active + * because it does not disturb other active substreams. + */ + if (!i2s->soc_info->shared_fifo_flush) { + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) + jz4740_i2s_set_bits(i2s, JZ_REG_AIC_CTRL, JZ_AIC_CTRL_TFLUSH); + else + jz4740_i2s_set_bits(i2s, JZ_REG_AIC_CTRL, JZ_AIC_CTRL_RFLUSH); + } + if (snd_soc_dai_active(dai)) return 0; - ctrl = jz4740_i2s_read(i2s, JZ_REG_AIC_CTRL); - ctrl |= JZ_AIC_CTRL_FLUSH; - jz4740_i2s_write(i2s, JZ_REG_AIC_CTRL, ctrl); + /* + * When there is a shared flush bit for both FIFOs, the TFLUSH + * bit flushes both FIFOs. Flushing while the DAI is active would + * cause FIFO underruns in other active substreams so we have to + * guard this behind the snd_soc_dai_active() check. + */ + if (i2s->soc_info->shared_fifo_flush) + jz4740_i2s_set_bits(i2s, JZ_REG_AIC_CTRL, JZ_AIC_CTRL_TFLUSH); ret = clk_prepare_enable(i2s->clk_i2s); if (ret) @@ -467,6 +495,7 @@ static struct snd_soc_dai_driver jz4740_ static const struct i2s_soc_info jz4740_i2s_soc_info = { .version = JZ_I2S_JZ4740, .dai = &jz4740_i2s_dai, + .shared_fifo_flush = true, }; static const struct i2s_soc_info jz4760_i2s_soc_info = {