[PATCH 2/2] net: ethernet: ti: cpsw: fix resume because of usage count

From: Ivan Khoronzhuk
Date: Wed Feb 08 2017 - 19:08:50 EST


The usage count function is based on ndev_running flag that is
updated before calling ndo_open/close, but if ndo is called in
another place, in this case in suspend/resume, the counter is not
changed, that breaks sus/resume. For common resource no difference
which device is using it, does matter only device count. So, replace
usage count function on var and inc and dec it in ndo_open/close.

Fixes: 03fd01ad0eead23eb79294b6fb4d71dcac493855
"net: ethernet: ti: cpsw: don't duplicate ndev_running"

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>
---
drivers/net/ethernet/ti/cpsw.c | 42 ++++++++++++------------------------------
1 file changed, 12 insertions(+), 30 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 9714fab..1ffaad1 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -399,6 +399,7 @@ struct cpsw_common {
struct cpts *cpts;
int rx_ch_num, tx_ch_num;
int speed;
+ int usage_count;
};

struct cpsw_priv {
@@ -671,18 +672,6 @@ static void cpsw_intr_disable(struct cpsw_common *cpsw)
return;
}

-static int cpsw_get_usage_count(struct cpsw_common *cpsw)
-{
- u32 i;
- u32 usage_count = 0;
-
- for (i = 0; i < cpsw->data.slaves; i++)
- if (cpsw->slaves[i].ndev && netif_running(cpsw->slaves[i].ndev))
- usage_count++;
-
- return usage_count;
-}
-
static void cpsw_tx_handler(void *token, int len, int status)
{
struct netdev_queue *txq;
@@ -716,8 +705,7 @@ static void cpsw_rx_handler(void *token, int len, int status)

if (unlikely(status < 0) || unlikely(!netif_running(ndev))) {
/* In dual emac mode check for all interfaces */
- if (cpsw->data.dual_emac &&
- cpsw_get_usage_count(cpsw) &&
+ if (cpsw->data.dual_emac && cpsw->usage_count &&
(status >= 0)) {
/* The packet received is for the interface which
* is already down and the other interface is up
@@ -1492,11 +1480,8 @@ static int cpsw_ndo_open(struct net_device *ndev)
CPSW_MAJOR_VERSION(reg), CPSW_MINOR_VERSION(reg),
CPSW_RTL_VERSION(reg));

- /* Initialize host and slave ports.
- * Given ndev is marked as opened already, so init port only if 1 ndev
- * is opened
- */
- if (cpsw_get_usage_count(cpsw) < 2)
+ /* Initialize host and slave ports */
+ if (!cpsw->usage_count)
cpsw_init_host_port(priv);
for_each_slave(priv, cpsw_slave_open, priv);

@@ -1507,10 +1492,8 @@ static int cpsw_ndo_open(struct net_device *ndev)
cpsw_ale_add_vlan(cpsw->ale, cpsw->data.default_vlan,
ALE_ALL_PORTS, ALE_ALL_PORTS, 0, 0);

- /* Given ndev is marked as opened already, so if more ndev
- * are opened - no need to init shared resources.
- */
- if (cpsw_get_usage_count(cpsw) < 2) {
+ /* initialize shared resources for every ndev */
+ if (!cpsw->usage_count) {
/* disable priority elevation */
__raw_writel(0, &cpsw->regs->ptype);

@@ -1552,6 +1535,7 @@ static int cpsw_ndo_open(struct net_device *ndev)

cpdma_ctlr_start(cpsw->dma);
cpsw_intr_enable(cpsw);
+ cpsw->usage_count++;

return 0;

@@ -1572,10 +1556,7 @@ static int cpsw_ndo_stop(struct net_device *ndev)
netif_tx_stop_all_queues(priv->ndev);
netif_carrier_off(priv->ndev);

- /* Given ndev is marked as close already,
- * so disable shared resources if no open devices
- */
- if (!cpsw_get_usage_count(cpsw)) {
+ if (cpsw->usage_count <= 1) {
napi_disable(&cpsw->napi_rx);
napi_disable(&cpsw->napi_tx);
cpts_unregister(cpsw->cpts);
@@ -1588,6 +1569,7 @@ static int cpsw_ndo_stop(struct net_device *ndev)
if (cpsw_need_resplit(cpsw))
cpsw_split_res(ndev);

+ cpsw->usage_count--;
pm_runtime_put_sync(cpsw->dev);
return 0;
}
@@ -2393,7 +2375,7 @@ static int cpsw_resume_data_pass(struct net_device *ndev)
netif_dormant_off(slave->ndev);

/* After this receive is started */
- if (cpsw_get_usage_count(cpsw)) {
+ if (cpsw->usage_count) {
ret = cpsw_fill_rx_channels(priv);
if (ret)
return ret;
@@ -2447,7 +2429,7 @@ static int cpsw_set_channels(struct net_device *ndev,
}
}

- if (cpsw_get_usage_count(cpsw))
+ if (cpsw->usage_count)
cpsw_split_res(ndev);

ret = cpsw_resume_data_pass(ndev);
@@ -2529,7 +2511,7 @@ static int cpsw_set_ringparam(struct net_device *ndev,

cpdma_set_num_rx_descs(cpsw->dma, ering->rx_pending);

- if (cpsw_get_usage_count(cpsw))
+ if (cpsw->usage_count)
cpdma_chan_split_pool(cpsw->dma);

ret = cpsw_resume_data_pass(ndev);
--
2.7.4