Commit 482ba7a6 authored by Thierry Reding's avatar Thierry Reding Committed by Greg Kroah-Hartman
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usb: host: xhci-tegra: Use CNR as firmware ready indicator 



The Falcon CPU state is a suboptimal indicator for firmware readiness,
since the Falcon can be in a running state if the firmware is handling
port state changes or running other tasks. Instead, the driver should
check the STS_CNR bit to determine whether or not the firmware has been
successfully loaded and is ready for XHCI operation.

Based on work by JC Kuo <jckuo@nvidia.com>.

Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20191206140653.2085561-5-thierry.reding@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ec12ac10

drivers/usb/host/xhci-tegra.c

+15 −12
Original line number Diff line number Diff line
@@ -830,10 +830,10 @@ static int tegra_xusb_request_firmware(struct tegra_xusb *tegra) 
static int tegra_xusb_load_firmware(struct tegra_xusb *tegra)

{

	unsigned int code_tag_blocks, code_size_blocks, code_blocks;

	struct xhci_cap_regs __iomem *cap = tegra->regs;

	struct tegra_xusb_fw_header *header;

	struct xhci_cap_regs __iomem *cap;

	struct xhci_op_regs __iomem *op;

	struct device *dev = tegra->dev;

	struct xhci_op_regs __iomem *op;

	unsigned long timeout;

	time64_t timestamp;

	struct tm time;
@@ -842,6 +842,7 @@ static int tegra_xusb_load_firmware(struct tegra_xusb *tegra) 
	int err;



	header = (struct tegra_xusb_fw_header *)tegra->fw.virt;

	op = tegra->regs + HC_LENGTH(readl(&cap->hc_capbase));



	if (csb_readl(tegra, XUSB_CSB_MP_ILOAD_BASE_LO) != 0) {

		dev_info(dev, "Firmware already loaded, Falcon state %#x\n",
@@ -911,21 +912,23 @@ static int tegra_xusb_load_firmware(struct tegra_xusb *tegra) 
	csb_writel(tegra, le32_to_cpu(header->boot_codetag),

		   XUSB_FALC_BOOTVEC);



	/* Boot Falcon CPU and wait for it to enter the STOPPED (idle) state. */

	timeout = jiffies + msecs_to_jiffies(5);



	/* Boot Falcon CPU and wait for USBSTS_CNR to get cleared. */

	csb_writel(tegra, CPUCTL_STARTCPU, XUSB_FALC_CPUCTL);



	while (time_before(jiffies, timeout)) {

		if (csb_readl(tegra, XUSB_FALC_CPUCTL) == CPUCTL_STATE_STOPPED)

	timeout = jiffies + msecs_to_jiffies(200);



	do {

		value = readl(&op->status);

		if ((value & STS_CNR) == 0)

			break;



		usleep_range(100, 200);

	}

		usleep_range(1000, 2000);

	} while (time_is_after_jiffies(timeout));



	if (csb_readl(tegra, XUSB_FALC_CPUCTL) != CPUCTL_STATE_STOPPED) {

		dev_err(dev, "Falcon failed to start, state: %#x\n",

			csb_readl(tegra, XUSB_FALC_CPUCTL));

	value = readl(&op->status);

	if (value & STS_CNR) {

		value = csb_readl(tegra, XUSB_FALC_CPUCTL);

		dev_err(dev, "XHCI controller not read: %#010x\n", value);

		return -EIO;

	}

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