DMA: PL08x: fix channel pausing to timeout rather than lockup

#include <linux/module.h>

#include <linux/interrupt.h>

#include <linux/slab.h>

#include <linux/delay.h>

#include <linux/dmapool.h>

#include <linux/dmaengine.h>

#include <linux/amba/bus.h>

}

/*

 * Overall DMAC remains enabled always.

 * Pause the channel by setting the HALT bit.

 *

 * Disabling individual channels could lose data.

 * For M->P transfers, pause the DMAC first and then stop the peripheral -

 * the FIFO can only drain if the peripheral is still requesting data.

 * (note: this can still timeout if the DMAC FIFO never drains of data.)

 *

 * Disable the peripheral DMA after disabling the DMAC in order to allow

 * the DMAC FIFO to drain, and hence allow the channel to show inactive

 * For P->M transfers, disable the peripheral first to stop it filling

 * the DMAC FIFO, and then pause the DMAC.

 */

static void pl08x_pause_phy_chan(struct pl08x_phy_chan *ch)

{

	u32 val;

	int timeout;

	/* Set the HALT bit and wait for the FIFO to drain */

	val = readl(ch->base + PL080_CH_CONFIG);

	writel(val, ch->base + PL080_CH_CONFIG);

	/* Wait for channel inactive */

	while (pl08x_phy_channel_busy(ch))

		cpu_relax();

	for (timeout = 1000; timeout; timeout--) {

		if (!pl08x_phy_channel_busy(ch))

			break;

		udelay(1);

	}

	if (pl08x_phy_channel_busy(ch))

		pr_err("pl08x: channel%u timeout waiting for pause\n", ch->id);

}

static void pl08x_resume_phy_chan(struct pl08x_phy_chan *ch)