[PATCH] ASoC: tegra: Fix build error due to 64-by-32 division

[PATCH] ASoC: tegra: Fix build error due to 64-by-32 division

[Sameer Pujar]

Build errors are seen on 32-bit platforms because of a plain 64-by-32
division. For example, following build erros were reported.

"ERROR: modpost: "__udivdi3" [sound/soc/tegra/snd-soc-tegra210-dmic.ko]
 undefined!"
"ERROR: modpost: "__divdi3" [sound/soc/tegra/snd-soc-tegra210-dmic.ko]
 undefined!"

This can be fixed by using div_u64() helper from 'math64.h' header.

Fixes: 8c8ff982e9e2 ("ASoC: tegra: Add Tegra210 based DMIC driver")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Sameer Pujar <spujar@nvidia.com>
---
 sound/soc/tegra/tegra210_dmic.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/soc/tegra/tegra210_dmic.c b/sound/soc/tegra/tegra210_dmic.c
index ff6fd65..d682414 100644
--- a/sound/soc/tegra/tegra210_dmic.c
+++ b/sound/soc/tegra/tegra210_dmic.c
@@ -6,6 +6,7 @@
 
 #include <linux/clk.h>
 #include <linux/device.h>
+#include <linux/math64.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
@@ -129,7 +130,7 @@ static int tegra210_dmic_hw_params(struct snd_pcm_substream *substream,
 	 * Boost Gain Volume control has 100x factor.
 	 */
 	if (dmic->boost_gain)
-		gain_q23 = (gain_q23 * dmic->boost_gain) / 100;
+		gain_q23 = div_u64(gain_q23 * dmic->boost_gain, 100);
 
 	regmap_write(dmic->regmap, TEGRA210_DMIC_LP_FILTER_GAIN,
 		     (unsigned int)gain_q23);
-- 
2.7.4

Re: [PATCH] ASoC: tegra: Fix build error due to 64-by-32 division

[Mark Brown]

On Thu, 23 Jul 2020 13:43:31 +0530, Sameer Pujar wrote:
> Build errors are seen on 32-bit platforms because of a plain 64-by-32
> division. For example, following build erros were reported.
> 
> "ERROR: modpost: "__udivdi3" [sound/soc/tegra/snd-soc-tegra210-dmic.ko]
>  undefined!"
> "ERROR: modpost: "__divdi3" [sound/soc/tegra/snd-soc-tegra210-dmic.ko]
>  undefined!"
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: tegra: Fix build error due to 64-by-32 division
      commit: f9ec176cd684c83a60638123da0b34c7c82f0c74

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

Re: [PATCH] ASoC: tegra: Fix build error due to 64-by-32 division

[Randy Dunlap]

On 7/23/20 1:13 AM, Sameer Pujar wrote:
> Build errors are seen on 32-bit platforms because of a plain 64-by-32
> division. For example, following build erros were reported.
> 
> "ERROR: modpost: "__udivdi3" [sound/soc/tegra/snd-soc-tegra210-dmic.ko]
>  undefined!"
> "ERROR: modpost: "__divdi3" [sound/soc/tegra/snd-soc-tegra210-dmic.ko]
>  undefined!"
> 
> This can be fixed by using div_u64() helper from 'math64.h' header.
> 
> Fixes: 8c8ff982e9e2 ("ASoC: tegra: Add Tegra210 based DMIC driver")
> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Reported-by: Randy Dunlap <rdunlap@infradead.org>
> Signed-off-by: Sameer Pujar <spujar@nvidia.com>
> ---
>  sound/soc/tegra/tegra210_dmic.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/sound/soc/tegra/tegra210_dmic.c b/sound/soc/tegra/tegra210_dmic.c
> index ff6fd65..d682414 100644
> --- a/sound/soc/tegra/tegra210_dmic.c
> +++ b/sound/soc/tegra/tegra210_dmic.c
> @@ -6,6 +6,7 @@
>  
>  #include <linux/clk.h>
>  #include <linux/device.h>
> +#include <linux/math64.h>
>  #include <linux/module.h>
>  #include <linux/of_device.h>
>  #include <linux/platform_device.h>
> @@ -129,7 +130,7 @@ static int tegra210_dmic_hw_params(struct snd_pcm_substream *substream,
>  	 * Boost Gain Volume control has 100x factor.
>  	 */
>  	if (dmic->boost_gain)
> -		gain_q23 = (gain_q23 * dmic->boost_gain) / 100;
> +		gain_q23 = div_u64(gain_q23 * dmic->boost_gain, 100);
>  
>  	regmap_write(dmic->regmap, TEGRA210_DMIC_LP_FILTER_GAIN,
>  		     (unsigned int)gain_q23);
> 

Yes, that fixes the division problem. Thanks.
Acked-by: Randy Dunlap <rdunlap@infradead.org>


Now I get these warnings:

  CC [M]  sound/soc/tegra/tegra210_dmic.o
../sound/soc/tegra/tegra210_dmic.c:55:12: warning: ‘tegra210_dmic_runtime_resume’ defined but not used [-Wunused-function]
 static int tegra210_dmic_runtime_resume(struct device *dev)
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
../sound/soc/tegra/tegra210_dmic.c:43:12: warning: ‘tegra210_dmic_runtime_suspend’ defined but not used [-Wunused-function]
 static int tegra210_dmic_runtime_suspend(struct device *dev)
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~


-- 
~Randy
Reported-by: Randy Dunlap <rdunlap@infradead.org>