x86: sysreset: Set up LPC only after relocation

Probing LPC can cause PCI enumeration to take place, which significantly
increases pre-relocation memory usage. Also, LPC is somtimes enabled
directly by SPL.

Adjust the logic to probe the LPC only after relocation. This allows
chromebook_link64 to start up without a much larger
CONFIG_SYS_MALLOC_F_LEN value.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/drivers/sysreset/sysreset_x86.c b/drivers/sysreset/sysreset_x86.c
index 8042f3994fe2e0f1be9048f3400504b97b653b19..4936fdb76c721426272c0a6d6ae36e7ea308e7e9 100644 (file)
--- a/drivers/sysreset/sysreset_x86.c
+++ b/drivers/sysreset/sysreset_x86.c
@@ -129,8 +129,13 @@ static int x86_sysreset_probe(struct udevice *dev)
 {
        struct x86_sysreset_plat *plat = dev_get_plat(dev);
 
-       /* Locate the PCH if there is one. It isn't essential */
-       uclass_first_device(UCLASS_PCH, &plat->pch);
+       /*
+        * Locate the PCH if there is one. It isn't essential. Avoid this before
+        * relocation as we shouldn't need reset then and it needs a lot of
+        * memory for PCI enumeration.
+        */
+       if (gd->flags & GD_FLG_RELOC)
+               uclass_first_device(UCLASS_PCH, &plat->pch);
 
        return 0;
 }