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Commit 2f575fcf authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Simon Horman
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ARM: shmobile: R-Car: Break infinite loop 



rcar_sysc_update() loops (with interrupts disabled and while holding a
spinlock) until submitting a power shutoff or resume request fails, or
until the submitted request was accepted.
If none of these conditions becomes true, this forms an infinite loop.

Put a limit on the maximum number of loop iterations, and add a small
delay to each iteration, to fix this.

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarSimon Horman <horms+renesas@verge.net.au>
parent 6fd2242e

arch/arm/mach-shmobile/pm-rcar.c

+14 −2
Original line number Diff line number Diff line
@@ -42,6 +42,9 @@ 
#define SYSCSR_RETRIES		100

#define SYSCSR_DELAY_US		1



#define PWRER_RETRIES		100

#define PWRER_DELAY_US		1



#define SYSCISR_RETRIES		1000

#define SYSCISR_DELAY_US	1
@@ -95,14 +98,23 @@ static int rcar_sysc_update(struct rcar_sysc_ch *sysc_ch, 
	iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);



	/* Submit power shutoff or resume request until it was accepted */

	do {

	for (k = 0; k < PWRER_RETRIES; k++) {

		ret = on_off_fn(sysc_ch);

		if (ret)

			goto out;



		status = ioread32(rcar_sysc_base +

				  sysc_ch->chan_offs + PWRER_OFFS);

	} while (status & chan_mask);

		if (!(status & chan_mask))

			break;



		udelay(PWRER_DELAY_US);

	}



	if (k == PWRER_RETRIES) {

		ret = -EIO;

		goto out;

	}



	/* Wait until the power shutoff or resume request has completed * */

	for (k = 0; k < SYSCISR_RETRIES; k++) {