oops with cs5530 using ide.2.2.17.all.20000904.patch (probably 2.4 as well)

When using Linux-2.2.17 + ide.2.2.17.all.20000904.patch on a board with the CS5530, doing the following generates a kernel NULL dereference:

pb-3com# cat /proc/ide/cs5530

Unable to handle kernel NULL pointer dereference at virtual address 0000003c

...

This is caused because the 'bmide_dev' in cs5530.c is NULL. This has been set wrongly because the 'dev' value used in pci_init_cs5530() is corrupted by the loop:

     for( dev = pci_devices; dev; dev=dev->next)
     {...}

A fix is to move the setting of the 'bmide_dev' value to before this loop.

A quick look at Linux-2.4.0-test9 shows it probably suffers from the same problem as well.

Below is a patch against Linux-2.2.17 + ide.2.2.17.all.20000904.patch

@@ -268,6 +268,14 @@
     unsigned short pcicmd = 0;
     unsigned long flags;
 
+#if defined(DISPLAY_CS5530_TIMINGS) && defined(CONFIG_PROC_FS)
+    if (!cs5530_proc) {
+         cs5530_proc = 1;
+         bmide_dev = dev;
+         cs5530_display_info = &cs5530_get_info;
+    }
+#endif /* DISPLAY_CS5530_TIMINGS && CONFIG_PROC_FS */
+
     for(dev = pci_devices; dev; dev=dev->next) {
          if (dev->vendor == PCI_VENDOR_ID_CYRIX) {
               switch (dev->device) {

@@ -337,14 +345,6 @@
     pci_write_config_byte(master_0, 0x43, 0xc1);
 
     restore_flags(flags);
-
-#if defined(DISPLAY_CS5530_TIMINGS) && defined(CONFIG_PROC_FS)
-    if (!cs5530_proc) {
-         cs5530_proc = 1;
-         bmide_dev = dev;
-         cs5530_display_info = &cs5530_get_info;
-    }
-#endif /* DISPLAY_CS5530_TIMINGS && CONFIG_PROC_FS */
 
     return 0;
 }

Jon

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