[PATCH v2 5/7] phy: cadence-torrent: Check total lane count for all subnodes is within limit

From: Swapnil Jakhade
Date: Thu Aug 27 2020 - 09:56:11 EST


Add checking if total number of lanes for all subnodes is not greater than
number of lanes supported by PHY.

Signed-off-by: Swapnil Jakhade <sjakhade@xxxxxxxxxxx>
---
drivers/phy/cadence/phy-cadence-torrent.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/phy/cadence/phy-cadence-torrent.c b/drivers/phy/cadence/phy-cadence-torrent.c
index 66ae5b749385..ed2140691077 100644
--- a/drivers/phy/cadence/phy-cadence-torrent.c
+++ b/drivers/phy/cadence/phy-cadence-torrent.c
@@ -25,7 +25,6 @@
#define REF_CLK_19_2MHz 19200000
#define REF_CLK_25MHz 25000000

-#define DEFAULT_NUM_LANES 4
#define MAX_NUM_LANES 4
#define DEFAULT_MAX_BIT_RATE 8100 /* in Mbps */

@@ -1735,6 +1734,7 @@ static int cdns_torrent_phy_probe(struct platform_device *pdev)
const struct cdns_torrent_data *data;
struct device_node *child;
int ret, subnodes, node = 0, i;
+ u32 total_num_lanes = 0;
u8 init_dp_regmap = 0;

/* Get init data for this PHY */
@@ -1809,9 +1809,15 @@ static int cdns_torrent_phy_probe(struct platform_device *pdev)
goto put_child;
}

- cdns_phy->phys[node].num_lanes = DEFAULT_NUM_LANES;
- of_property_read_u32(child, "cdns,num-lanes",
- &cdns_phy->phys[node].num_lanes);
+ if (of_property_read_u32(child, "cdns,num-lanes",
+ &cdns_phy->phys[node].num_lanes)) {
+ dev_err(dev, "%s: No \"cdns,num-lanes\"-property.\n",
+ child->full_name);
+ ret = -EINVAL;
+ goto put_child;
+ }
+
+ total_num_lanes += cdns_phy->phys[node].num_lanes;

if (cdns_phy->phys[node].phy_type == PHY_TYPE_DP) {
switch (cdns_phy->phys[node].num_lanes) {
@@ -1893,6 +1899,11 @@ static int cdns_torrent_phy_probe(struct platform_device *pdev)
}
cdns_phy->nsubnodes = node;

+ if (total_num_lanes > MAX_NUM_LANES) {
+ dev_err(dev, "Invalid lane configuration\n");
+ goto put_lnk_rst;
+ }
+
phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
if (IS_ERR(phy_provider)) {
ret = PTR_ERR(phy_provider);
--
2.26.1