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Subject[RFC 03/19] HSI: ssi_protocol: avoid ssi_waketest call with held spinlock
Date
This avoids calling ssi_waketest(), while a spinlock is
being hold, since ssi_waketest may sleep once irq_safe
runtime pm is disabled.

Signed-off-by: Sebastian Reichel <sre@kernel.org>
---
drivers/hsi/clients/ssi_protocol.c | 41 +++++++++++++++++++++++---------------
1 file changed, 25 insertions(+), 16 deletions(-)

diff --git a/drivers/hsi/clients/ssi_protocol.c b/drivers/hsi/clients/ssi_protocol.c
index 6595d2091268..8534efda8140 100644
--- a/drivers/hsi/clients/ssi_protocol.c
+++ b/drivers/hsi/clients/ssi_protocol.c
@@ -88,6 +88,8 @@ void ssi_waketest(struct hsi_client *cl, unsigned int enable);
#define SSIP_READY_CMD SSIP_CMD(SSIP_READY, 0)
#define SSIP_SWBREAK_CMD SSIP_CMD(SSIP_SW_BREAK, 0)

+#define SSIP_WAKETEST_FLAG 0
+
/* Main state machine states */
enum {
INIT,
@@ -116,7 +118,7 @@ enum {
* @main_state: Main state machine
* @send_state: TX state machine
* @recv_state: RX state machine
- * @waketest: Flag to follow wake line test
+ * @flags: Flags, currently only used to follow wake line test
* @rxid: RX data id
* @txid: TX data id
* @txqueue_len: TX queue length
@@ -137,7 +139,7 @@ struct ssi_protocol {
unsigned int main_state;
unsigned int send_state;
unsigned int recv_state;
- unsigned int waketest:1;
+ unsigned long flags;
u8 rxid;
u8 txid;
unsigned int txqueue_len;
@@ -405,15 +407,17 @@ static void ssip_reset(struct hsi_client *cl)
spin_lock_bh(&ssi->lock);
if (ssi->send_state != SEND_IDLE)
hsi_stop_tx(cl);
- if (ssi->waketest)
- ssi_waketest(cl, 0);
+ spin_unlock_bh(&ssi->lock);
+ if (test_and_clear_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
+ ssi_waketest(cl, 0); /* FIXME: To be removed */
+ spin_lock_bh(&ssi->lock);
del_timer(&ssi->rx_wd);
del_timer(&ssi->tx_wd);
del_timer(&ssi->keep_alive);
ssi->main_state = 0;
ssi->send_state = 0;
ssi->recv_state = 0;
- ssi->waketest = 0;
+ ssi->flags = 0;
ssi->rxid = 0;
ssi->txid = 0;
list_for_each_safe(head, tmp, &ssi->txqueue) {
@@ -437,7 +441,8 @@ static void ssip_dump_state(struct hsi_client *cl)
dev_err(&cl->device, "Send state: %d\n", ssi->send_state);
dev_err(&cl->device, "CMT %s\n", (ssi->main_state == ACTIVE) ?
"Online" : "Offline");
- dev_err(&cl->device, "Wake test %d\n", ssi->waketest);
+ dev_err(&cl->device, "Wake test %d\n",
+ test_bit(SSIP_WAKETEST_FLAG, &ssi->flags));
dev_err(&cl->device, "Data RX id: %d\n", ssi->rxid);
dev_err(&cl->device, "Data TX id: %d\n", ssi->txid);

@@ -668,10 +673,12 @@ static void ssip_rx_bootinforeq(struct hsi_client *cl, u32 cmd)
case HANDSHAKE:
spin_lock(&ssi->lock);
ssi->main_state = HANDSHAKE;
- if (!ssi->waketest) {
- ssi->waketest = 1;
+ spin_unlock(&ssi->lock);
+
+ if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
ssi_waketest(cl, 1); /* FIXME: To be removed */
- }
+
+ spin_lock(&ssi->lock);
/* Start boot handshake watchdog */
mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
spin_unlock(&ssi->lock);
@@ -718,10 +725,12 @@ static void ssip_rx_waketest(struct hsi_client *cl, u32 cmd)
spin_unlock(&ssi->lock);
return;
}
- if (ssi->waketest) {
- ssi->waketest = 0;
+ spin_unlock(&ssi->lock);
+
+ if (test_and_clear_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
ssi_waketest(cl, 0); /* FIXME: To be removed */
- }
+
+ spin_lock(&ssi->lock);
ssi->main_state = ACTIVE;
del_timer(&ssi->tx_wd); /* Stop boot handshake timer */
spin_unlock(&ssi->lock);
@@ -926,11 +935,11 @@ static int ssip_pn_open(struct net_device *dev)
}
dev_dbg(&cl->device, "Configuring SSI port\n");
hsi_setup(cl);
- spin_lock_bh(&ssi->lock);
- if (!ssi->waketest) {
- ssi->waketest = 1;
+
+ if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
ssi_waketest(cl, 1); /* FIXME: To be removed */
- }
+
+ spin_lock_bh(&ssi->lock);
ssi->main_state = HANDSHAKE;
spin_unlock_bh(&ssi->lock);

--
2.8.1
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