Revision b85bfa246efd24ea3fdb5ee949c28e3110c6d299 authored by Daniel Kurtz on 22 September 2018, 19:58:26 UTC, committed by Linus Walleij on 25 September 2018, 10:39:19 UTC
From the AMD BKDG, if WAKE_INT_MASTER_REG.MaskStsEn is set, a software
write to the debounce registers of *any* gpio will block wake/interrupt
status generation for *all* gpios for a length of time that depends on
WAKE_INT_MASTER_REG.MaskStsLength[11:0].  During this period the Interrupt
Delivery bit (INTERRUPT_ENABLE) will read as 0.

In commit 4c1de0414a1340 ("pinctrl/amd: poll InterruptEnable bits in
enable_irq") we tried to fix this same "gpio Interrupts are blocked
immediately after writing debounce registers" problem, but incorrectly
assumed it only affected the gpio whose debounce was being configured
and not ALL gpios.

To solve this for all gpios, we move the polling loop from
amd_gpio_irq_enable() to amd_gpio_irq_set_type(), while holding the gpio
spinlock.  This ensures that another gpio operation (e.g.
amd_gpio_irq_unmask()) can read a temporarily disabled IRQ and
incorrectly disable it while trying to modify some other register bits.

Fixes: 4c1de0414a1340 pinctrl/amd: poll InterruptEnable bits in enable_irq
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
1 parent 6bf4ca7
Raw File
rose_dev.c
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
 */
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/sysctl.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/in.h>
#include <linux/if_ether.h>
#include <linux/slab.h>

#include <asm/io.h>

#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>

#include <net/ip.h>
#include <net/arp.h>

#include <net/ax25.h>
#include <net/rose.h>

static int rose_header(struct sk_buff *skb, struct net_device *dev,
		       unsigned short type,
		       const void *daddr, const void *saddr, unsigned int len)
{
	unsigned char *buff = skb_push(skb, ROSE_MIN_LEN + 2);

	if (daddr)
		memcpy(buff + 7, daddr, dev->addr_len);

	*buff++ = ROSE_GFI | ROSE_Q_BIT;
	*buff++ = 0x00;
	*buff++ = ROSE_DATA;
	*buff++ = 0x7F;
	*buff++ = AX25_P_IP;

	if (daddr != NULL)
		return 37;

	return -37;
}

static int rose_set_mac_address(struct net_device *dev, void *addr)
{
	struct sockaddr *sa = addr;
	int err;

	if (!memcmp(dev->dev_addr, sa->sa_data, dev->addr_len))
		return 0;

	if (dev->flags & IFF_UP) {
		err = rose_add_loopback_node((rose_address *)sa->sa_data);
		if (err)
			return err;

		rose_del_loopback_node((rose_address *)dev->dev_addr);
	}

	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);

	return 0;
}

static int rose_open(struct net_device *dev)
{
	int err;

	err = rose_add_loopback_node((rose_address *)dev->dev_addr);
	if (err)
		return err;

	netif_start_queue(dev);

	return 0;
}

static int rose_close(struct net_device *dev)
{
	netif_stop_queue(dev);
	rose_del_loopback_node((rose_address *)dev->dev_addr);
	return 0;
}

static netdev_tx_t rose_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct net_device_stats *stats = &dev->stats;
	unsigned int len = skb->len;

	if (!netif_running(dev)) {
		printk(KERN_ERR "ROSE: rose_xmit - called when iface is down\n");
		return NETDEV_TX_BUSY;
	}

	if (!rose_route_frame(skb, NULL)) {
		dev_kfree_skb(skb);
		stats->tx_errors++;
		return NETDEV_TX_OK;
	}

	stats->tx_packets++;
	stats->tx_bytes += len;
	return NETDEV_TX_OK;
}

static const struct header_ops rose_header_ops = {
	.create	= rose_header,
};

static const struct net_device_ops rose_netdev_ops = {
	.ndo_open		= rose_open,
	.ndo_stop		= rose_close,
	.ndo_start_xmit		= rose_xmit,
	.ndo_set_mac_address    = rose_set_mac_address,
};

void rose_setup(struct net_device *dev)
{
	dev->mtu		= ROSE_MAX_PACKET_SIZE - 2;
	dev->netdev_ops		= &rose_netdev_ops;

	dev->header_ops		= &rose_header_ops;
	dev->hard_header_len	= AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN;
	dev->addr_len		= ROSE_ADDR_LEN;
	dev->type		= ARPHRD_ROSE;

	/* New-style flags. */
	dev->flags		= IFF_NOARP;
}
back to top