[alsa-devel] [PATCH v2 0/2] Relax bitclk computation when using PLL
Using strict bitclk requirements we cannot support all promised rates and formats. For this reason we relax bitclk computation by choosing the best available bitclk.
First patch in the series is based on Arnd's patch:
http://mailman.alsa-project.org/pipermail/alsa-devel/2017-April/119899.html
Second one does the actual bitclk relaxation.
Daniel Baluta (2): ASoC: codec: wm9860: avoid maybe-uninitialized warning ASoC: codec: wm8960: Relax bit clock computation when using PLL
sound/soc/codecs/wm8960.c | 36 +++++++++++++++++++++--------------- 1 file changed, 21 insertions(+), 15 deletions(-)
The new PLL configuration code triggers a harmless warning:
sound/soc/codecs/wm8960.c: In function 'wm8960_configure_clocking': sound/soc/codecs/wm8960.c:735:3: error: 'best_freq_out' may be used uninitialized in this function [-Werror=maybe-uninitialized] wm8960_set_pll(codec, freq_in, best_freq_out); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ sound/soc/codecs/wm8960.c:699:12: note: 'best_freq_out' was declared here
Fix this by reworking the code such that:
1) When there is no PLL freq available return -EINVAL and make sure *bclk_idx, *dac_idx, *sysclk_idx are initialized with invalid values.
2) When there is a PLL freq available initialize *bclk_idx, *dac_idx and *sysclk_idx with correct values and immediately return the freq available.
Fixes: 84fdc00d519f ("ASoC: codec: wm9860: Refactor PLL out freq search") Fixes: 303e8954af8d ("ASoC: codec: wm8960: Stop when a matching PLL freq is found") Suggested-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Daniel Baluta daniel.baluta@nxp.com --- Changes since v1: * use return instead of break * update commit message
sound/soc/codecs/wm8960.c | 26 +++++++++----------------- 1 file changed, 9 insertions(+), 17 deletions(-)
diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c index ace69da..d899623 100644 --- a/sound/soc/codecs/wm8960.c +++ b/sound/soc/codecs/wm8960.c @@ -686,7 +686,7 @@ int wm8960_configure_sysclk(struct wm8960_priv *wm8960, int mclk, * @bclk_idx: bclk_divs index for found bclk * * Returns: - * -1, in case no PLL frequency out available was found + * < 0, in case no PLL frequency out available was found * >=0, in case we could derive bclk, lrclk, sysclk from PLL out using * (@sysclk_idx, @dac_idx, @bclk_idx) dividers */ @@ -696,13 +696,13 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in, { struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec); int sysclk, bclk, lrclk, freq_out; - int diff, best_freq_out; + int diff; int i, j, k;
bclk = wm8960->bclk; lrclk = wm8960->lrclk;
- *bclk_idx = -1; + *sysclk_idx = *dac_idx = *bclk_idx = -1;
for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) { if (sysclk_divs[i] == -1) @@ -720,21 +720,12 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in, *sysclk_idx = i; *dac_idx = j; *bclk_idx = k; - best_freq_out = freq_out; - break; + return freq_out; } } - if (k != ARRAY_SIZE(bclk_divs)) - break; } - if (j != ARRAY_SIZE(dac_divs)) - break; } - - if (*bclk_idx != -1) - wm8960_set_pll(codec, freq_in, best_freq_out); - - return *bclk_idx; + return -EINVAL; } static int wm8960_configure_clocking(struct snd_soc_codec *codec) { @@ -783,11 +774,12 @@ static int wm8960_configure_clocking(struct snd_soc_codec *codec) } }
- ret = wm8960_configure_pll(codec, freq_in, &i, &j, &k); - if (ret < 0) { + freq_out = wm8960_configure_pll(codec, freq_in, &i, &j, &k); + if (freq_out < 0) { dev_err(codec->dev, "failed to configure clock via PLL\n"); - return -EINVAL; + return freq_out; } + wm8960_set_pll(codec, freq_in, freq_out);
configure_clock: /* configure sysclk clock */
Bitclk is derived from sysclk using bclk_divs. Sysclk can be derived in two ways: (1) directly from MLCK (2) MCLK via PLL
Commit 3c01b9ee2ab9d0d ("ASoC: codec: wm8960: Relax bit clock computation") relaxed bitclk computation when sysclk is directly derived from MCLK.
Lets do the same thing when sysclk is derived via PLL.
Signed-off-by: Daniel Baluta daniel.baluta@nxp.com --- Changes since v2: * rebase after changes in first patch in the series
sound/soc/codecs/wm8960.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c index d899623..9ed4557 100644 --- a/sound/soc/codecs/wm8960.c +++ b/sound/soc/codecs/wm8960.c @@ -679,6 +679,10 @@ int wm8960_configure_sysclk(struct wm8960_priv *wm8960, int mclk, * - freq_out = sysclk * sysclk_divs * - 10 * sysclk = bclk * bclk_divs * + * If we cannot find an exact match for (sysclk, lrclk, bclk) + * triplet, we relax the bclk such that bclk is chosen as the + * closest available frequency greater than expected bclk. + * * @codec: codec structure * @freq_in: input frequency used to derive freq out via PLL * @sysclk_idx: sysclk_divs index for found sysclk @@ -696,12 +700,14 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in, { struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec); int sysclk, bclk, lrclk, freq_out; - int diff; + int diff, closest, best_freq_out; int i, j, k;
bclk = wm8960->bclk; lrclk = wm8960->lrclk; + closest = freq_in;
+ best_freq_out = -EINVAL; *sysclk_idx = *dac_idx = *bclk_idx = -1;
for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) { @@ -722,10 +728,18 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in, *bclk_idx = k; return freq_out; } + if (diff > 0 && closest > diff) { + *sysclk_idx = i; + *dac_idx = j; + *bclk_idx = k; + closest = diff; + best_freq_out = freq_out; + } } } } - return -EINVAL; + + return best_freq_out; } static int wm8960_configure_clocking(struct snd_soc_codec *codec) {
On Wed, Apr 26, 2017 at 3:09 PM, Daniel Baluta daniel.baluta@nxp.com wrote:
The new PLL configuration code triggers a harmless warning:
sound/soc/codecs/wm8960.c: In function 'wm8960_configure_clocking': sound/soc/codecs/wm8960.c:735:3: error: 'best_freq_out' may be used uninitialized in this function [-Werror=maybe-uninitialized] wm8960_set_pll(codec, freq_in, best_freq_out); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ sound/soc/codecs/wm8960.c:699:12: note: 'best_freq_out' was declared here
Fix this by reworking the code such that:
- When there is no PLL freq available return -EINVAL and make
sure *bclk_idx, *dac_idx, *sysclk_idx are initialized with invalid values.
- When there is a PLL freq available initialize *bclk_idx,
*dac_idx and *sysclk_idx with correct values and immediately return the freq available.
Fixes: 84fdc00d519f ("ASoC: codec: wm9860: Refactor PLL out freq search") Fixes: 303e8954af8d ("ASoC: codec: wm8960: Stop when a matching PLL freq is found") Suggested-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Daniel Baluta daniel.baluta@nxp.com
Looks good to me. Let me know if you need me to test this more thoroughly with randconfig builds, otherwise I'll assume it's fine and it will get tested once it shows up in linux-next.
Acked-by: Arnd Bergmann arnd@arndb.de
Thanks for addressing this,
Arnd
On Jo, 2017-04-27 at 12:07 +0200, Arnd Bergmann wrote:
On Wed, Apr 26, 2017 at 3:09 PM, Daniel Baluta <daniel.baluta@nxp.com
wrote:
The new PLL configuration code triggers a harmless warning:
sound/soc/codecs/wm8960.c: In function 'wm8960_configure_clocking': sound/soc/codecs/wm8960.c:735:3: error: 'best_freq_out' may be used uninitialized in this function [-Werror=maybe-uninitialized] wm8960_set_pll(codec, freq_in, best_freq_out); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ sound/soc/codecs/wm8960.c:699:12: note: 'best_freq_out' was declared here
Fix this by reworking the code such that:
- When there is no PLL freq available return -EINVAL and make
sure *bclk_idx, *dac_idx, *sysclk_idx are initialized with invalid values.
- When there is a PLL freq available initialize *bclk_idx,
*dac_idx and *sysclk_idx with correct values and immediately return the freq available.
Fixes: 84fdc00d519f ("ASoC: codec: wm9860: Refactor PLL out freq search") Fixes: 303e8954af8d ("ASoC: codec: wm8960: Stop when a matching PLL freq is found") Suggested-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Daniel Baluta daniel.baluta@nxp.com
Looks good to me. Let me know if you need me to test this more thoroughly with randconfig builds, otherwise I'll assume it's fine and it will get tested once it shows up in linux-next.
Acked-by: Arnd Bergmann arnd@arndb.de
Hi Arnd,
Thanks for doing this. I wouldn't expect randconfigs builds to show other issues.
Anyhow, would like to see if with your compiler there are no warnings for the second patch of the series:
http://mailman.alsa-project.org/pipermail/alsa-devel/2017-April/120177.html
thanks, Daniel.
On Thu, Apr 27, 2017 at 1:02 PM, Daniel Baluta daniel.baluta@nxp.com wrote:
On Jo, 2017-04-27 at 12:07 +0200, Arnd Bergmann wrote:
On Wed, Apr 26, 2017 at 3:09 PM, Daniel Baluta <daniel.baluta@nxp.com
wrote:
The new PLL configuration code triggers a harmless warning:
sound/soc/codecs/wm8960.c: In function 'wm8960_configure_clocking': sound/soc/codecs/wm8960.c:735:3: error: 'best_freq_out' may be used uninitialized in this function [-Werror=maybe-uninitialized] wm8960_set_pll(codec, freq_in, best_freq_out); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ sound/soc/codecs/wm8960.c:699:12: note: 'best_freq_out' was declared here
Fix this by reworking the code such that:
- When there is no PLL freq available return -EINVAL and make
sure *bclk_idx, *dac_idx, *sysclk_idx are initialized with invalid values.
- When there is a PLL freq available initialize *bclk_idx,
*dac_idx and *sysclk_idx with correct values and immediately return the freq available.
Fixes: 84fdc00d519f ("ASoC: codec: wm9860: Refactor PLL out freq search") Fixes: 303e8954af8d ("ASoC: codec: wm8960: Stop when a matching PLL freq is found") Suggested-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Daniel Baluta daniel.baluta@nxp.com
Looks good to me. Let me know if you need me to test this more thoroughly with randconfig builds, otherwise I'll assume it's fine and it will get tested once it shows up in linux-next.
Acked-by: Arnd Bergmann arnd@arndb.de
Hi Arnd,
Thanks for doing this. I wouldn't expect randconfigs builds to show other issues.
Anyhow, would like to see if with your compiler there are no warnings for the second patch of the series:
http://mailman.alsa-project.org/pipermail/alsa-devel/2017-April/120177.html
I've applied both patches to my randconfig tree now. The configuration that first showed the problem works fine now, but with -Wmaybe-uninitialized warnings I try to do additional randconfig tests as sometimes the warnings come back depending on some other inlining decisions or optimization flags.
Arnd
The patch
ASoC: codec: wm8960: Relax bit clock computation when using PLL
has been applied to the asoc tree at
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying to this mail.
Thanks, Mark
From 82bab88910ee358305a2f31ab30dad59f1b6421c Mon Sep 17 00:00:00 2001
From: Daniel Baluta daniel.baluta@nxp.com Date: Wed, 26 Apr 2017 16:09:52 +0300 Subject: [PATCH] ASoC: codec: wm8960: Relax bit clock computation when using PLL
Bitclk is derived from sysclk using bclk_divs. Sysclk can be derived in two ways: (1) directly from MLCK (2) MCLK via PLL
Commit 3c01b9ee2ab9d0d ("ASoC: codec: wm8960: Relax bit clock computation") relaxed bitclk computation when sysclk is directly derived from MCLK.
Lets do the same thing when sysclk is derived via PLL.
Signed-off-by: Daniel Baluta daniel.baluta@nxp.com Signed-off-by: Mark Brown broonie@kernel.org --- sound/soc/codecs/wm8960.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c index d899623fb101..9ed455700954 100644 --- a/sound/soc/codecs/wm8960.c +++ b/sound/soc/codecs/wm8960.c @@ -679,6 +679,10 @@ int wm8960_configure_sysclk(struct wm8960_priv *wm8960, int mclk, * - freq_out = sysclk * sysclk_divs * - 10 * sysclk = bclk * bclk_divs * + * If we cannot find an exact match for (sysclk, lrclk, bclk) + * triplet, we relax the bclk such that bclk is chosen as the + * closest available frequency greater than expected bclk. + * * @codec: codec structure * @freq_in: input frequency used to derive freq out via PLL * @sysclk_idx: sysclk_divs index for found sysclk @@ -696,12 +700,14 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in, { struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec); int sysclk, bclk, lrclk, freq_out; - int diff; + int diff, closest, best_freq_out; int i, j, k;
bclk = wm8960->bclk; lrclk = wm8960->lrclk; + closest = freq_in;
+ best_freq_out = -EINVAL; *sysclk_idx = *dac_idx = *bclk_idx = -1;
for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) { @@ -722,10 +728,18 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in, *bclk_idx = k; return freq_out; } + if (diff > 0 && closest > diff) { + *sysclk_idx = i; + *dac_idx = j; + *bclk_idx = k; + closest = diff; + best_freq_out = freq_out; + } } } } - return -EINVAL; + + return best_freq_out; } static int wm8960_configure_clocking(struct snd_soc_codec *codec) {
The patch
ASoC: codec: wm9860: avoid maybe-uninitialized warning
has been applied to the asoc tree at
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying to this mail.
Thanks, Mark
From 66772eda0edbfbbbe7767a6b5d07e09dae84403d Mon Sep 17 00:00:00 2001
From: Daniel Baluta daniel.baluta@nxp.com Date: Wed, 26 Apr 2017 16:09:51 +0300 Subject: [PATCH] ASoC: codec: wm9860: avoid maybe-uninitialized warning
The new PLL configuration code triggers a harmless warning:
sound/soc/codecs/wm8960.c: In function 'wm8960_configure_clocking': sound/soc/codecs/wm8960.c:735:3: error: 'best_freq_out' may be used uninitialized in this function [-Werror=maybe-uninitialized] wm8960_set_pll(codec, freq_in, best_freq_out); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ sound/soc/codecs/wm8960.c:699:12: note: 'best_freq_out' was declared here
Fix this by reworking the code such that:
1) When there is no PLL freq available return -EINVAL and make sure *bclk_idx, *dac_idx, *sysclk_idx are initialized with invalid values.
2) When there is a PLL freq available initialize *bclk_idx, *dac_idx and *sysclk_idx with correct values and immediately return the freq available.
Fixes: 84fdc00d519f ("ASoC: codec: wm9860: Refactor PLL out freq search") Fixes: 303e8954af8d ("ASoC: codec: wm8960: Stop when a matching PLL freq is found") Suggested-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Daniel Baluta daniel.baluta@nxp.com Acked-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Mark Brown broonie@kernel.org --- sound/soc/codecs/wm8960.c | 26 +++++++++----------------- 1 file changed, 9 insertions(+), 17 deletions(-)
diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c index ace69da97cb8..d899623fb101 100644 --- a/sound/soc/codecs/wm8960.c +++ b/sound/soc/codecs/wm8960.c @@ -686,7 +686,7 @@ int wm8960_configure_sysclk(struct wm8960_priv *wm8960, int mclk, * @bclk_idx: bclk_divs index for found bclk * * Returns: - * -1, in case no PLL frequency out available was found + * < 0, in case no PLL frequency out available was found * >=0, in case we could derive bclk, lrclk, sysclk from PLL out using * (@sysclk_idx, @dac_idx, @bclk_idx) dividers */ @@ -696,13 +696,13 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in, { struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec); int sysclk, bclk, lrclk, freq_out; - int diff, best_freq_out; + int diff; int i, j, k;
bclk = wm8960->bclk; lrclk = wm8960->lrclk;
- *bclk_idx = -1; + *sysclk_idx = *dac_idx = *bclk_idx = -1;
for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) { if (sysclk_divs[i] == -1) @@ -720,21 +720,12 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in, *sysclk_idx = i; *dac_idx = j; *bclk_idx = k; - best_freq_out = freq_out; - break; + return freq_out; } } - if (k != ARRAY_SIZE(bclk_divs)) - break; } - if (j != ARRAY_SIZE(dac_divs)) - break; } - - if (*bclk_idx != -1) - wm8960_set_pll(codec, freq_in, best_freq_out); - - return *bclk_idx; + return -EINVAL; } static int wm8960_configure_clocking(struct snd_soc_codec *codec) { @@ -783,11 +774,12 @@ static int wm8960_configure_clocking(struct snd_soc_codec *codec) } }
- ret = wm8960_configure_pll(codec, freq_in, &i, &j, &k); - if (ret < 0) { + freq_out = wm8960_configure_pll(codec, freq_in, &i, &j, &k); + if (freq_out < 0) { dev_err(codec->dev, "failed to configure clock via PLL\n"); - return -EINVAL; + return freq_out; } + wm8960_set_pll(codec, freq_in, freq_out);
configure_clock: /* configure sysclk clock */
participants (3)
-
Arnd Bergmann -
Daniel Baluta -
Mark Brown