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Date: Mon, 2 Nov 2015 18:48:33 +0800
From: <shh.xie@...il.com>
To: <netdev@...r.kernel.org>, <davem@...emloft.net>
CC: <f.fainelli@...il.com>, Shaohui Xie <Shaohui.Xie@...escale.com>
Subject: [PATCH][v2] net: phy: fix a bug in get_phy_c45_ids
From: Shaohui Xie <Shaohui.Xie@...escale.com>
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@...escale.com>
---
changes in v2:
1. uses a helper function to read devices in package registers of a MMD.
2. rewrites the probing loop with using the helper function.
drivers/net/phy/phy_device.c | 74 +++++++++++++++++++++++++++++---------------
1 file changed, 49 insertions(+), 25 deletions(-)
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 3833891..8c84b9e 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;
}
}
}
--
2.1.0.27.g96db324
--
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