Commit 2158e856 authored by Robert Hancock's avatar Robert Hancock Committed by David S. Miller

net: sfp: add mutex to prevent concurrent state checks

sfp_check_state can potentially be called by both a threaded IRQ handler
and delayed work. If it is concurrently called, it could result in
incorrect state management. Add a st_mutex to protect the state - this
lock gets taken outside of code that checks and handle state changes, and
the existing sm_mutex nests inside of it.
Suggested-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarRobert Hancock <hancock@sedsystems.ca>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 257c2559
......@@ -188,10 +188,11 @@ struct sfp {
int gpio_irq[GPIO_MAX];
bool attached;
struct mutex st_mutex; /* Protects state */
unsigned int state;
struct delayed_work poll;
struct delayed_work timeout;
struct mutex sm_mutex;
struct mutex sm_mutex; /* Protects state machine */
unsigned char sm_mod_state;
unsigned char sm_dev_state;
unsigned short sm_state;
......@@ -1721,6 +1722,7 @@ static void sfp_check_state(struct sfp *sfp)
{
unsigned int state, i, changed;
mutex_lock(&sfp->st_mutex);
state = sfp_get_state(sfp);
changed = state ^ sfp->state;
changed &= SFP_F_PRESENT | SFP_F_LOS | SFP_F_TX_FAULT;
......@@ -1746,6 +1748,7 @@ static void sfp_check_state(struct sfp *sfp)
sfp_sm_event(sfp, state & SFP_F_LOS ?
SFP_E_LOS_HIGH : SFP_E_LOS_LOW);
rtnl_unlock();
mutex_unlock(&sfp->st_mutex);
}
static irqreturn_t sfp_irq(int irq, void *data)
......@@ -1776,6 +1779,7 @@ static struct sfp *sfp_alloc(struct device *dev)
sfp->dev = dev;
mutex_init(&sfp->sm_mutex);
mutex_init(&sfp->st_mutex);
INIT_DELAYED_WORK(&sfp->poll, sfp_poll);
INIT_DELAYED_WORK(&sfp->timeout, sfp_timeout);
......
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