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authorShaohui Xie <Shaohui.Xie@freescale.com>2015-11-03 12:27:33 +0800
committerDavid S. Miller <davem@davemloft.net>2015-11-02 23:45:20 -0500
commit5f6c99e0ab805d8ec9eda105822912d49aa1d409 (patch)
tree1a584383b2a07a88e8ba3081e30aed14b2e408c5 /drivers/net/phy
parentb2663a4f30e85ec606b806f5135413e6d5c78d1e (diff)
downloadlinux-linaro-stable-5f6c99e0ab805d8ec9eda105822912d49aa1d409.tar.gz
net: phy: fix a bug in get_phy_c45_ids
When probing devices-in-package for a c45 phy, device zero is the last device to probe, however, if driver reads 0 from device zero, c45_ids->devices_in_package is set to '0', the loop condition of probing will be matched again, see codes below: for (i = 1;i < num_ids && c45_ids->devices_in_package == 0;i++) driver will run in a dead loop. This patch restructures the bug and confusing loop, it provides a helper function get_phy_c45_devs_in_pkg which to read devices-in-package registers of a MMD, and rewrites the loop with using the helper function. Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/phy')
-rw-r--r--drivers/net/phy/phy_device.c74
1 files changed, 49 insertions, 25 deletions
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index f761288abe66..0a76cc5d13da 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -205,6 +205,37 @@ struct phy_device *phy_device_create(struct mii_bus *bus, int addr, int phy_id,
}
EXPORT_SYMBOL(phy_device_create);
+/* get_phy_c45_devs_in_pkg - reads a MMD's devices in package registers.
+ * @bus: the target MII bus
+ * @addr: PHY address on the MII bus
+ * @dev_addr: MMD address in the PHY.
+ * @devices_in_package: where to store the devices in package information.
+ *
+ * Description: reads devices in package registers of a MMD at @dev_addr
+ * from PHY at @addr on @bus.
+ *
+ * Returns: 0 on success, -EIO on failure.
+ */
+static int get_phy_c45_devs_in_pkg(struct mii_bus *bus, int addr, int dev_addr,
+ u32 *devices_in_package)
+{
+ int phy_reg, reg_addr;
+
+ reg_addr = MII_ADDR_C45 | dev_addr << 16 | MDIO_DEVS2;
+ phy_reg = mdiobus_read(bus, addr, reg_addr);
+ if (phy_reg < 0)
+ return -EIO;
+ *devices_in_package = (phy_reg & 0xffff) << 16;
+
+ reg_addr = MII_ADDR_C45 | dev_addr << 16 | MDIO_DEVS1;
+ phy_reg = mdiobus_read(bus, addr, reg_addr);
+ if (phy_reg < 0)
+ return -EIO;
+ *devices_in_package |= (phy_reg & 0xffff);
+
+ return 0;
+}
+
/**
* get_phy_c45_ids - reads the specified addr for its 802.3-c45 IDs.
* @bus: the target MII bus
@@ -223,38 +254,31 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id,
int phy_reg;
int i, reg_addr;
const int num_ids = ARRAY_SIZE(c45_ids->device_ids);
+ u32 *devs = &c45_ids->devices_in_package;
- /* Find first non-zero Devices In package. Device
- * zero is reserved, so don't probe it.
+ /* Find first non-zero Devices In package. Device zero is reserved
+ * for 802.3 c45 complied PHYs, so don't probe it at first.
*/
- for (i = 1;
- i < num_ids && c45_ids->devices_in_package == 0;
- i++) {
-retry: reg_addr = MII_ADDR_C45 | i << 16 | MDIO_DEVS2;
- phy_reg = mdiobus_read(bus, addr, reg_addr);
+ for (i = 1; i < num_ids && *devs == 0; i++) {
+ phy_reg = get_phy_c45_devs_in_pkg(bus, addr, i, devs);
if (phy_reg < 0)
return -EIO;
- c45_ids->devices_in_package = (phy_reg & 0xffff) << 16;
- reg_addr = MII_ADDR_C45 | i << 16 | MDIO_DEVS1;
- phy_reg = mdiobus_read(bus, addr, reg_addr);
- if (phy_reg < 0)
- return -EIO;
- c45_ids->devices_in_package |= (phy_reg & 0xffff);
-
- if ((c45_ids->devices_in_package & 0x1fffffff) == 0x1fffffff) {
- if (i) {
- /* If mostly Fs, there is no device there,
- * then let's continue to probe more, as some
- * 10G PHYs have zero Devices In package,
- * e.g. Cortina CS4315/CS4340 PHY.
- */
- i = 0;
- goto retry;
- } else {
- /* no device there, let's get out of here */
+ if ((*devs & 0x1fffffff) == 0x1fffffff) {
+ /* If mostly Fs, there is no device there,
+ * then let's continue to probe more, as some
+ * 10G PHYs have zero Devices In package,
+ * e.g. Cortina CS4315/CS4340 PHY.
+ */
+ phy_reg = get_phy_c45_devs_in_pkg(bus, addr, 0, devs);
+ if (phy_reg < 0)
+ return -EIO;
+ /* no device there, let's get out of here */
+ if ((*devs & 0x1fffffff) == 0x1fffffff) {
*phy_id = 0xffffffff;
return 0;
+ } else {
+ break;
}
}
}