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authorQuentin Schulz <quentin.schulz@cherry.de>2025-05-27 13:56:23 +0200
committerPaolo Abeni <pabeni@redhat.com>2025-05-29 10:51:43 +0200
commiteb7fd7aa35bfcc1e1fda4ecc42ccfcb526cdc780 (patch)
tree1bd298a5a76a77208a53186636224545032ab9d5
parentpage_pool: Fix use-after-free in page_pool_recycle_in_ring (diff)
downloadlinux-rng-eb7fd7aa35bfcc1e1fda4ecc42ccfcb526cdc780.tar.xz
linux-rng-eb7fd7aa35bfcc1e1fda4ecc42ccfcb526cdc780.zip
net: stmmac: platform: guarantee uniqueness of bus_id
bus_id is currently derived from the ethernetX alias. If one is missing for the device, 0 is used. If ethernet0 points to another stmmac device or if there are 2+ stmmac devices without an ethernet alias, then bus_id will be 0 for all of those. This is an issue because the bus_id is used to generate the mdio bus id (new_bus->id in drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c stmmac_mdio_register) and this needs to be unique. This allows to avoid needing to define ethernet aliases for devices with multiple stmmac controllers (such as the Rockchip RK3588) for multiple stmmac devices to probe properly. Obviously, the bus_id isn't guaranteed to be stable across reboots if no alias is set for the device but that is easily fixed by simply adding an alias if this is desired. Fixes: 25c83b5c2e82 ("dt:net:stmmac: Add support to dwmac version 3.610 and 3.710") Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de> Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Link: https://patch.msgid.link/20250527-stmmac-mdio-bus_id-v2-1-a5ca78454e3c@cherry.de Signed-off-by: Paolo Abeni <pabeni@redhat.com>
-rw-r--r--drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 43c869f64c39..b80c1efdb323 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -430,6 +430,7 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
struct device_node *np = pdev->dev.of_node;
struct plat_stmmacenet_data *plat;
struct stmmac_dma_cfg *dma_cfg;
+ static int bus_id = -ENODEV;
int phy_mode;
void *ret;
int rc;
@@ -465,8 +466,14 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
of_property_read_u32(np, "max-speed", &plat->max_speed);
plat->bus_id = of_alias_get_id(np, "ethernet");
- if (plat->bus_id < 0)
- plat->bus_id = 0;
+ if (plat->bus_id < 0) {
+ if (bus_id < 0)
+ bus_id = of_alias_get_highest_id("ethernet");
+ /* No ethernet alias found, init at -1 so first bus_id is 0 */
+ if (bus_id < 0)
+ bus_id = -1;
+ plat->bus_id = ++bus_id;
+ }
/* Default to phy auto-detection */
plat->phy_addr = -1;