sfc: Reduce delays in SFE4001 initialisation

Currently the board initialisation includes 2 delays of 1 second each.
Usually it is unnecessary to wait that long, so check before doing so.

Correct some of the comments and log messages while we're here.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 35 insertions, 22 deletions

diff --git a/drivers/net/sfc/sfe4001.c b/drivers/net/sfc/sfe4001.c
index b2784952399..f9272816437 100644
--- a/drivers/net/sfc/sfe4001.c
+++ b/drivers/net/sfc/sfe4001.c
@@ -145,7 +145,7 @@ MODULE_PARM_DESC(phy_flash_cfg,
 int sfe4001_init(struct efx_nic *efx)
 {
         struct i2c_client *hwmon_client, *ioexp_client;
-        unsigned int count;
+        unsigned int i, j;
         int rc;
         u8 out;
         efx_dword_t reg;
@@ -209,17 +209,24 @@ int sfe4001_init(struct efx_nic *efx)
         if (rc)
                 goto fail_on;
 
-        /* Turn all power off then wait 1 sec. This ensures PHY is reset */
+        /* If PHY power is on, turn it all off and wait 1 second to
+         * ensure a full reset.
+         */
+        rc = i2c_smbus_read_byte_data(ioexp_client, P0_OUT);
+        if (rc < 0)
+                goto fail_on;
         out = 0xff & ~((0 << P0_EN_1V2_LBN) | (0 << P0_EN_2V5_LBN) |
                        (0 << P0_EN_3V3X_LBN) | (0 << P0_EN_5V_LBN) |
                        (0 << P0_EN_1V0X_LBN));
-        rc = i2c_smbus_write_byte_data(ioexp_client, P0_OUT, out);
-        if (rc)
-                goto fail_on;
+        if (rc != out) {
+                EFX_INFO(efx, "power-cycling PHY\n");
+                rc = i2c_smbus_write_byte_data(ioexp_client, P0_OUT, out);
+                if (rc)
+                        goto fail_on;
+                schedule_timeout_uninterruptible(HZ);
+        }
 
-        schedule_timeout_uninterruptible(HZ);
-        count = 0;
-        do {
+        for (i = 0; i < 20; ++i) {
                 /* Turn on 1.2V, 2.5V, 3.3V and 5V power rails */
                 out = 0xff & ~((1 << P0_EN_1V2_LBN) | (1 << P0_EN_2V5_LBN) |
                                (1 << P0_EN_3V3X_LBN) | (1 << P0_EN_5V_LBN) |
@@ -238,23 +245,29 @@ int sfe4001_init(struct efx_nic *efx)
                 if (rc)
                         goto fail_on;
 
-                EFX_INFO(efx, "waiting for power (attempt %d)...\n", count);
-
-                schedule_timeout_uninterruptible(HZ);
-
-                /* Check DSP is powered */
-                rc = i2c_smbus_read_byte_data(ioexp_client, P1_IN);
-                if (rc < 0)
-                        goto fail_on;
-                if (rc & (1 << P1_AFE_PWD_LBN))
-                        goto done;
+                EFX_INFO(efx, "waiting for DSP boot (attempt %d)...\n", i);
 
-                /* DSP doesn't look powered in flash config mode */
-                if (sfe4001_phy_flash_cfg)
+                /* In flash config mode, DSP does not turn on AFE, so
+                 * just wait 1 second.
+                 */
+                if (sfe4001_phy_flash_cfg) {
+                        schedule_timeout_uninterruptible(HZ);
                         goto done;
-        } while (++count < 20);
+                }
+
+                for (j = 0; j < 10; ++j) {
+                        msleep(100);
+
+                        /* Check DSP has asserted AFE power line */
+                        rc = i2c_smbus_read_byte_data(ioexp_client, P1_IN);
+                        if (rc < 0)
+                                goto fail_on;
+                        if (rc & (1 << P1_AFE_PWD_LBN))
+                                goto done;
+                }
+        }
 
-        EFX_INFO(efx, "timed out waiting for power\n");
+        EFX_INFO(efx, "timed out waiting for DSP boot\n");
         rc = -ETIMEDOUT;
         goto fail_on;