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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>
This commit is contained in:
Shaohui Xie 2015-11-03 12:27:33 +08:00 committed by David S. Miller
parent b2663a4f30
commit 5f6c99e0ab
1 changed files with 49 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

74
drivers/net/phy/phy_device.c
View File

@ -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;
}
}
}