[alsa-devel] Applied "ASoC: Intel: Common: Update dsp register poll implementation" to the asoc tree

[Mark Brown]

The patch

   ASoC: Intel: Common: Update dsp register poll implementation

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 9cc8f9fe0f9e84771f2872f8939d37414ef9d58d Mon Sep 17 00:00:00 2001
From: Jeeja KP <jeeja.kp at intel.com>
Date: Mon, 2 Jan 2017 09:50:02 +0530
Subject: [PATCH] ASoC: Intel: Common: Update dsp register poll implementation

Poll implementation is not quite accurate, especially for smaller
values of timeout or timeout values close to the actual timeout needed

Use jiffies to set the timeout value and time_before() to get the
accurate time. So update the dsp register poll implementation to
provide accurate timeout using jiffies.

Signed-off-by: Jayachandran B <jayachandran.b at intel.com>
Signed-off-by: Jeeja KP <jeeja.kp at intel.com>
Acked-by: Vinod Koul <vinod.koul at intel.com>
Signed-off-by: Mark Brown <broonie at kernel.org>
---
 sound/soc/intel/common/sst-dsp.c | 52 ++++++++++++++++++++--------------------
 1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/sound/soc/intel/common/sst-dsp.c b/sound/soc/intel/common/sst-dsp.c
index c00ede4ea4d7..11c0805393ff 100644
--- a/sound/soc/intel/common/sst-dsp.c
+++ b/sound/soc/intel/common/sst-dsp.c
@@ -252,44 +252,44 @@ void sst_dsp_shim_update_bits_forced(struct sst_dsp *sst, u32 offset,
 EXPORT_SYMBOL_GPL(sst_dsp_shim_update_bits_forced);
 
 int sst_dsp_register_poll(struct sst_dsp *ctx, u32 offset, u32 mask,
-			 u32 target, u32 timeout, char *operation)
+			 u32 target, u32 time, char *operation)
 {
-	int time, ret;
 	u32 reg;
-	bool done = false;
+	unsigned long timeout;
+	int k = 0, s = 500;
 
 	/*
-	 * we will poll for couple of ms using mdelay, if not successful
-	 * then go to longer sleep using usleep_range
+	 * split the loop into sleeps of varying resolution. more accurately,
+	 * the range of wakeups are:
+	 * Phase 1(first 5ms): min sleep 0.5ms; max sleep 1ms.
+	 * Phase 2:( 5ms to 10ms) : min sleep 0.5ms; max sleep 10ms
+	 * (usleep_range (500, 1000) and usleep_range(5000, 10000) are
+	 * both possible in this phase depending on whether k > 10 or not).
+	 * Phase 3: (beyond 10 ms) min sleep 5ms; max sleep 10ms.
 	 */
 
-	/* check if set state successful */
-	for (time = 0; time < 5; time++) {
-		if ((sst_dsp_shim_read_unlocked(ctx, offset) & mask) == target) {
-			done = true;
-			break;
-		}
-		mdelay(1);
+	timeout = jiffies + msecs_to_jiffies(time);
+	while (((sst_dsp_shim_read_unlocked(ctx, offset) & mask) != target)
+		&& time_before(jiffies, timeout)) {
+		k++;
+		if (k > 10)
+			s = 5000;
+
+		usleep_range(s, 2*s);
 	}
 
-	if (done ==  false) {
-		/* sleeping in 10ms steps so adjust timeout value */
-		timeout /= 10;
+	reg = sst_dsp_shim_read_unlocked(ctx, offset);
 
-		for (time = 0; time < timeout; time++) {
-			if ((sst_dsp_shim_read_unlocked(ctx, offset) & mask) == target)
-				break;
+	if ((reg & mask) == target) {
+		dev_dbg(ctx->dev, "FW Poll Status: reg=%#x %s successful\n",
+					reg, operation);
 
-			usleep_range(5000, 10000);
-		}
+		return 0;
 	}
 
-	reg = sst_dsp_shim_read_unlocked(ctx, offset);
-	dev_dbg(ctx->dev, "FW Poll Status: reg=%#x %s %s\n", reg, operation,
-			(time < timeout) ? "successful" : "timedout");
-	ret = time < timeout ? 0 : -ETIME;
-
-	return ret;
+	dev_dbg(ctx->dev, "FW Poll Status: reg=%#x %s timedout\n",
+					reg, operation);
+	return -ETIME;
 }
 EXPORT_SYMBOL_GPL(sst_dsp_register_poll);
 
-- 
2.11.0