hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

net/smsc911x: Check if PHY is in operational mode before software reset 

SMSC LAN generation 4 chips integrate an IEEE 802.3 ethernet physical layer.
The PHY driver for this integrated chip enable an energy detect power-down mode.
When the PHY is in a power-down mode, it prevents the MAC portion chip to be
software reseted.

That means that if we compile the kernel with the configuration option SMSC_PHY
enabled and try to bring the network interface up without an cable plug-ed the
PHY will be in a low power mode and the software reset will fail returning -EIO
to user-space:

root@igep00x0:~# ifconfig eth0 up
ifconfig: SIOCSIFFLAGS: Input/output error

This patch disable the energy detect power-down mode before trying to software
reset the LAN chip and re-enables after it was reseted successfully.

Signed-off-by: Javier Martinez Canillas <javier@dowhile0.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Javier Martinez Canillas 2012-01-03 13:36:19 +00:00 committed by David S. Miller
parent 43c6759e73
commit 6386994e03
1 changed files with 92 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

92
drivers/net/ethernet/smsc/smsc911x.c
View File

@ -1319,10 +1319,92 @@ static void smsc911x_rx_multicast_update_workaround(struct smsc911x_data *pdata)
spin_unlock(&pdata->mac_lock);
}
static int smsc911x_phy_disable_energy_detect(struct smsc911x_data *pdata)
{
int rc = 0;
if (!pdata->phy_dev)
return rc;
rc = phy_read(pdata->phy_dev, MII_LAN83C185_CTRL_STATUS);
if (rc < 0) {
SMSC_WARN(pdata, drv, "Failed reading PHY control reg");
return rc;
}
/*
* If energy is detected the PHY is already awake so is not necessary
* to disable the energy detect power-down mode.
*/
if ((rc & MII_LAN83C185_EDPWRDOWN) &&
!(rc & MII_LAN83C185_ENERGYON)) {
/* Disable energy detect mode for this SMSC Transceivers */
rc = phy_write(pdata->phy_dev, MII_LAN83C185_CTRL_STATUS,
rc & (~MII_LAN83C185_EDPWRDOWN));
if (rc < 0) {
SMSC_WARN(pdata, drv, "Failed writing PHY control reg");
return rc;
}
mdelay(1);
}
return 0;
}
static int smsc911x_phy_enable_energy_detect(struct smsc911x_data *pdata)
{
int rc = 0;
if (!pdata->phy_dev)
return rc;
rc = phy_read(pdata->phy_dev, MII_LAN83C185_CTRL_STATUS);
if (rc < 0) {
SMSC_WARN(pdata, drv, "Failed reading PHY control reg");
return rc;
}
/* Only enable if energy detect mode is already disabled */
if (!(rc & MII_LAN83C185_EDPWRDOWN)) {
mdelay(100);
/* Enable energy detect mode for this SMSC Transceivers */
rc = phy_write(pdata->phy_dev, MII_LAN83C185_CTRL_STATUS,
rc | MII_LAN83C185_EDPWRDOWN);
if (rc < 0) {
SMSC_WARN(pdata, drv, "Failed writing PHY control reg");
return rc;
}
mdelay(1);
}
return 0;
}
static int smsc911x_soft_reset(struct smsc911x_data *pdata)
{
unsigned int timeout;
unsigned int temp;
int ret;
/*
* LAN9210/LAN9211/LAN9220/LAN9221 chips have an internal PHY that
* are initialized in a Energy Detect Power-Down mode that prevents
* the MAC chip to be software reseted. So we have to wakeup the PHY
* before.
*/
if (pdata->generation == 4) {
ret = smsc911x_phy_disable_energy_detect(pdata);
if (ret) {
SMSC_WARN(pdata, drv, "Failed to wakeup the PHY chip");
return ret;
}
}
/* Reset the LAN911x */
smsc911x_reg_write(pdata, HW_CFG, HW_CFG_SRST_);
@ -1336,6 +1418,16 @@ static int smsc911x_soft_reset(struct smsc911x_data *pdata)
SMSC_WARN(pdata, drv, "Failed to complete reset");
return -EIO;
}
if (pdata->generation == 4) {
ret = smsc911x_phy_enable_energy_detect(pdata);
if (ret) {
SMSC_WARN(pdata, drv, "Failed to wakeup the PHY chip");
return ret;
}
}
return 0;
}