Author: ranma
Date: Wed Nov 24 20:57:08 2010
New Revision: 6121
URL: https://tracker.coreboot.org/trac/coreboot/changeset/6121

Log:
With low serial console loglevels a pcie graphics card is not
initialized properly because the pcie link takes some time to come
up.

I set the timeout rather arbitrary to 100ms, this is what a BIOS_ERR
and higher only boot looks like on my system (with pcie printks set
to BIOS_ERR so they show up):

|Device error
|Device error
|PCI: 00:02.0 PCIe link up after 35800 us
|PCI: 00:03.0 PCIe link up after 12900 us
|PCI: 00:03.1 PCIe link timeout
|PCI: 00:03.2 PCIe link up after 32000 us
|APIC: 00 missing read_resources
|I2C: 01:50 missing read_resources
|I2C: 01:51 missing read_resources
|I2C: 01:52 missing read_resources
|I2C: 01:53 missing read_resources
|Start bios (version pre-0.6.2-20101025_023503-nukunuku)

Signed-off-by: Tobias Diedrich <[email protected]>
Acked-by: Stefan Reinauer <[email protected]>

Modified:
   trunk/src/southbridge/via/k8t890/k8t890_pcie.c

Modified: trunk/src/southbridge/via/k8t890/k8t890_pcie.c
==============================================================================
--- trunk/src/southbridge/via/k8t890/k8t890_pcie.c      Wed Nov 24 01:39:44 
2010        (r6120)
+++ trunk/src/southbridge/via/k8t890/k8t890_pcie.c      Wed Nov 24 20:57:08 
2010        (r6121)
@@ -22,6 +22,7 @@
 #include <device/pci.h>
 #include <device/pciexp.h>
 #include <device/pci_ids.h>
+#include <delay.h>
 #include "k8t890.h"
 
 /*
@@ -30,16 +31,10 @@
  * http://linux.via.com.tw/
  */
 
-static void peg_init(struct device *dev)
+static void pcie_common_init(struct device *dev)
 {
        u8 reg;
-
-       printk(BIOS_DEBUG, "Configuring PCIe PEG\n");
-       dump_south(dev);
-
-       /* Disable link. */
-       reg = pci_read_config8(dev, 0x50);
-       pci_write_config8(dev, 0x50, reg | 0x10);
+       int i, up;
 
        /* Disable downstream read cycle retry,
         * otherwise the bus scan will hang if no device is plugged in. */
@@ -60,14 +55,48 @@
         */
        pci_write_config8(dev, 0xe1, 0xb);
 
+       /* Set replay timer limit. */
+       pci_write_config8(dev, 0xb1, 0xf0);
+
+       /* Enable link. */
+       reg = pci_read_config8(dev, 0x50);
+       pci_write_config8(dev, 0x50, reg & ~0x10);
+
+       /* Wait up to 100ms for link to come up */
+       up = 0;
+       for (i=0; i<1000; i++) {
+               if (pci_read_config16(dev, 0x52) & (1<<13)) {
+                       up = 1;
+                       break;
+               }
+               udelay(100);
+       }
+
+       printk(BIOS_SPEW, "%s PCIe link ", dev_path(dev));
+       if (up)
+               printk(BIOS_SPEW, "up after %d us\n", i*100);
+       else
+               printk(BIOS_SPEW, "timeout\n");
+
+       dump_south(dev);
+}
+
+static void peg_init(struct device *dev)
+{
+       u8 reg;
+
+       printk(BIOS_DEBUG, "Configuring PCIe PEG\n");
+       dump_south(dev);
+
+       /* Disable link. */
+       reg = pci_read_config8(dev, 0x50);
+       pci_write_config8(dev, 0x50, reg | 0x10);
+
        /*
         * pci_write_config8(dev, 0xe2, 0x0);
         * pci_write_config8(dev, 0xe3, 0x92);
         */
 
-       /* Set replay timer limit. */
-       pci_write_config8(dev, 0xb1, 0xf0);
-
        /* Bit0 = 1 SDP (Start DLLP) always at Lane0. */
        reg = pci_read_config8(dev, 0xb8);
        pci_write_config8(dev, 0xb8, reg | 0x1);
@@ -79,11 +108,7 @@
        reg = pci_read_config8(dev, 0xa4);
        pci_write_config8(dev, 0xa4, reg | 0x30);
 
-       /* Enable link. */
-       reg = pci_read_config8(dev, 0x50);
-       pci_write_config8(dev, 0x50, reg & ~0x10);
-
-       dump_south(dev);
+       pcie_common_init(dev);
 }
 
 static void pcie_init(struct device *dev)
@@ -97,33 +122,7 @@
        reg = pci_read_config8(dev, 0x50);
        pci_write_config8(dev, 0x50, reg | 0x10);
 
-       /* Disable downstream read cycle retry,
-        * otherwise the bus scan will hang if no device is plugged in. */
-       reg = pci_read_config8(dev, 0xa3);
-       pci_write_config8(dev, 0xa3, reg & ~0x01);
-
-       /* Use PHY negotiation for lane config */
-       reg = pci_read_config8(dev, 0xc1);
-       pci_write_config8(dev, 0xc1, reg & ~0x1f);
-
-       /* Award has 0xb, VIA recommends 0xd, default 0x8.
-        * bit4: receive polarity change control
-        * bits3:2: squelch window select 64~175mv
-        * bit1: Number of non-idle bits detected before exiting idle state
-        *       0: 10 bits, 1: 2 bits
-        * bit0: Number of idle bits detected before entering idle state
-        *       0: 10 bits, 1: 2 bits
-        */
-       pci_write_config8(dev, 0xe1, 0xb);
-
-       /* Set replay timer limit. */
-       pci_write_config8(dev, 0xb1, 0xf0);
-
-       /* Enable link. */
-       reg = pci_read_config8(dev, 0x50);
-       pci_write_config8(dev, 0x50, reg & ~0x10);
-
-       dump_south(dev);
+       pcie_common_init(dev);
 }
 
 static const struct device_operations peg_ops = {

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