Patch "clk: at91: pmc: Wait for clocks when resuming" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

clk: at91: pmc: Wait for clocks when resuming

to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
clk-at91-pmc-wait-for-clocks-when-resuming.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Romain Izard <[email protected]>
Date: Mon, 11 Dec 2017 17:55:33 +0100
Subject: clk: at91: pmc: Wait for clocks when resuming

From: Romain Izard <[email protected]>

[ Upstream commit 960e1c4d93be86d3b118fe22d4edc69e401b28b5 ]

Wait for the syncronization of all clocks when resuming, not only the UPLL clock. Do not use regmap_read_poll_timeout, as it will call BUG() when interrupts are masked, which is the case in here.

---
 drivers/clk/at91/pmc.c |   24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

@@ -107,10 +107,20 @@ static int pmc_suspend(void)
 	return 0;
 }
 
+static bool pmc_ready(unsigned int mask)
+{
+	unsigned int status;
+
+	regmap_read(pmcreg, AT91_PMC_SR, &status);
+
+	return ((status & mask) == mask) ? 1 : 0;
+}
+
 static void pmc_resume(void)
 {
-	int i, ret = 0;
+	int i;
 	u32 tmp;
+	u32 mask = AT91_PMC_MCKRDY | AT91_PMC_LOCKA;
 
 	regmap_read(pmcreg, AT91_PMC_MCKR, &tmp);
 	if (pmc_cache.mckr != tmp)

@@ -134,13 +144,11 @@ static void pmc_resume(void)
 			     AT91_PMC_PCR_CMD);
 	}
 
-	if (pmc_cache.uckr & AT91_PMC_UPLLEN) {
-		ret = regmap_read_poll_timeout(pmcreg, AT91_PMC_SR, tmp,
-					       !(tmp & AT91_PMC_LOCKU),
-					       10, 5000);
-		if (ret)
-			pr_crit("USB PLL didn't lock when resuming\n");
-	}
+	if (pmc_cache.uckr & AT91_PMC_UPLLEN)
+		mask |= AT91_PMC_LOCKU;
+
+	while (!pmc_ready(mask))
+		cpu_relax();
 }
 
 static struct syscore_ops pmc_syscore_ops = {

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/clk-at91-pmc-wait-for-clocks-when-resuming.patch