[PATCH] ASoC: AMD: Restore PME_EN state at Power On

[PATCH] ASoC: AMD: Restore PME_EN state at Power On

[Akshu Agrawal]

PME_EN state needs to restored to the value set by fmw.
For the devices which are not using I2S wake event which gets
enabled by PME_EN bit, keeping PME_EN enabled burns considerable amount
of power as it blocks low power state.
For the devices using I2S wake event, PME_EN gets enabled in fmw and the
state should be maintained after ACP Power On.

Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
---
 sound/soc/amd/raven/pci-acp3x.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/sound/soc/amd/raven/pci-acp3x.c b/sound/soc/amd/raven/pci-acp3x.c
index ebf4388b6262..31b797c8bfe6 100644
--- a/sound/soc/amd/raven/pci-acp3x.c
+++ b/sound/soc/amd/raven/pci-acp3x.c
@@ -19,10 +19,12 @@ struct acp3x_dev_data {
 	bool acp3x_audio_mode;
 	struct resource *res;
 	struct platform_device *pdev[ACP3x_DEVS];
+	u32 pme_en;
 };
 
-static int acp3x_power_on(void __iomem *acp3x_base)
+static int acp3x_power_on(struct acp3x_dev_data *adata)
 {
+	void __iomem *acp3x_base = adata->acp3x_base;
 	u32 val;
 	int timeout;
 
@@ -39,10 +41,10 @@ static int acp3x_power_on(void __iomem *acp3x_base)
 	while (++timeout < 500) {
 		val = rv_readl(acp3x_base + mmACP_PGFSM_STATUS);
 		if (!val) {
-			/* Set PME_EN as after ACP power On,
-			 * PME_EN gets cleared
+			/* ACP power On clears PME_EN.
+			 * Restore the value to its prior state
 			 */
-			rv_writel(0x1, acp3x_base + mmACP_PME_EN);
+			rv_writel(adata->pme_en, acp3x_base + mmACP_PME_EN);
 			return 0;
 		}
 		udelay(1);
@@ -74,12 +76,13 @@ static int acp3x_reset(void __iomem *acp3x_base)
 	return -ETIMEDOUT;
 }
 
-static int acp3x_init(void __iomem *acp3x_base)
+static int acp3x_init(struct acp3x_dev_data *adata)
 {
+	void __iomem *acp3x_base = adata->acp3x_base;
 	int ret;
 
 	/* power on */
-	ret = acp3x_power_on(acp3x_base);
+	ret = acp3x_power_on(adata);
 	if (ret) {
 		pr_err("ACP3x power on failed\n");
 		return ret;
@@ -151,7 +154,9 @@ static int snd_acp3x_probe(struct pci_dev *pci,
 	}
 	pci_set_master(pci);
 	pci_set_drvdata(pci, adata);
-	ret = acp3x_init(adata->acp3x_base);
+	/* Save ACP_PME_EN state */
+	adata->pme_en = rv_readl(adata->acp3x_base + mmACP_PME_EN);
+	ret = acp3x_init(adata);
 	if (ret)
 		goto disable_msi;
 
@@ -274,7 +279,7 @@ static int snd_acp3x_resume(struct device *dev)
 	struct acp3x_dev_data *adata;
 
 	adata = dev_get_drvdata(dev);
-	ret = acp3x_init(adata->acp3x_base);
+	ret = acp3x_init(adata);
 	if (ret) {
 		dev_err(dev, "ACP init failed\n");
 		return ret;
-- 
2.20.1

Re: [PATCH] ASoC: AMD: Restore PME_EN state at Power On

[Mark Brown]

On Sat, 25 Jul 2020 01:25:52 +0530, Akshu Agrawal wrote:
> PME_EN state needs to restored to the value set by fmw.
> For the devices which are not using I2S wake event which gets
> enabled by PME_EN bit, keeping PME_EN enabled burns considerable amount
> of power as it blocks low power state.
> For the devices using I2S wake event, PME_EN gets enabled in fmw and the
> state should be maintained after ACP Power On.

Applied to

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

Thanks!

[1/1] ASoC: AMD: Restore PME_EN state at Power On
      commit: 1255296cf0233780b7b9af90f374983fbcdef7bb

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