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Commit 0486a063 authored by Ivan Vecera's avatar Ivan Vecera Committed by David S. Miller
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tg3: prevent ifup/ifdown during PCI error recovery 



The patch fixes race conditions between PCI error recovery callbacks and
potential ifup/ifdown.

First, if ifup (tg3_open) is called between tg3_io_error_detected() and
tg3_io_resume() then tp->timer is armed twice before expiry. Once during
tg3_open() and again during tg3_io_resume(). This results in BUG
at kernel/time/timer.c:945.

Second, if ifdown (tg3_close) is called between tg3_io_error_detected()
and tg3_io_resume() then tg3_napi_disable() is called twice without
a tg3_napi_enable between. Once during tg3_io_error_detected() and again
during tg3_close(). The tg3_io_resume() then hangs on rtnl_lock().

v2: Added logging messages per Prashant's request

Cc: Prashant Sreedharan <prashant@broadcom.com>
Cc: Michael Chan <mchan@broadcom.com>

Signed-off-by: default avatarIvan Vecera <ivecera@redhat.com>
Acked-by: default avatarPrashant Sreedharan <prashant@broadcom.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 88e41947

drivers/net/ethernet/broadcom/tg3.c

+16 −0
Original line number Diff line number Diff line
@@ -11617,6 +11617,12 @@ static int tg3_open(struct net_device *dev) 
	struct tg3 *tp = netdev_priv(dev);

	int err;



	if (tp->pcierr_recovery) {

		netdev_err(dev, "Failed to open device. PCI error recovery "

			   "in progress\n");

		return -EAGAIN;

	}



	if (tp->fw_needed) {

		err = tg3_request_firmware(tp);

		if (tg3_asic_rev(tp) == ASIC_REV_57766) {
@@ -11674,6 +11680,12 @@ static int tg3_close(struct net_device *dev) 
{

	struct tg3 *tp = netdev_priv(dev);



	if (tp->pcierr_recovery) {

		netdev_err(dev, "Failed to close device. PCI error recovery "

			   "in progress\n");

		return -EAGAIN;

	}



	tg3_ptp_fini(tp);



	tg3_stop(tp);
@@ -17561,6 +17573,7 @@ static int tg3_init_one(struct pci_dev *pdev, 
	tp->rx_mode = TG3_DEF_RX_MODE;

	tp->tx_mode = TG3_DEF_TX_MODE;

	tp->irq_sync = 1;

	tp->pcierr_recovery = false;



	if (tg3_debug > 0)

		tp->msg_enable = tg3_debug;
@@ -18071,6 +18084,8 @@ static pci_ers_result_t tg3_io_error_detected(struct pci_dev *pdev, 


	rtnl_lock();



	tp->pcierr_recovery = true;



	/* We probably don't have netdev yet */

	if (!netdev || !netif_running(netdev))

		goto done;
@@ -18195,6 +18210,7 @@ static void tg3_io_resume(struct pci_dev *pdev) 
	tg3_phy_start(tp);



done:

	tp->pcierr_recovery = false;

	rtnl_unlock();

}

drivers/net/ethernet/broadcom/tg3.h

+1 −0
Original line number Diff line number Diff line
@@ -3407,6 +3407,7 @@ struct tg3 { 


	struct device			*hwmon_dev;

	bool				link_up;

	bool				pcierr_recovery;

};



/* Accessor macros for chip and asic attributes