X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=arch%2Fx86%2Fcpu%2Fqueensbay%2Ftnc.c;h=b226e4c5fd623694aeaeafc9387810cfec2554d9;hb=d19c90747d8975a523489f863984c521ae72ce39;hp=f9fddc1ba7645ade8246f116a77e3aa7a5f82c3c;hpb=efd633ccdd06361f63f9b8918eee647ceb65283d;p=u-boot

diff --git a/arch/x86/cpu/queensbay/tnc.c b/arch/x86/cpu/queensbay/tnc.c
index f9fddc1ba7..b226e4c5fd 100644
--- a/arch/x86/cpu/queensbay/tnc.c
+++ b/arch/x86/cpu/queensbay/tnc.c
@@ -5,17 +5,34 @@
  */
 
 #include <common.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <pci.h>
 #include <asm/io.h>
 #include <asm/irq.h>
-#include <asm/pci.h>
 #include <asm/post.h>
 #include <asm/arch/device.h>
 #include <asm/arch/tnc.h>
 #include <asm/fsp/fsp_support.h>
 #include <asm/processor.h>
 
-static void __maybe_unused disable_igd(void)
+static int __maybe_unused disable_igd(void)
 {
+	struct udevice *igd, *sdvo;
+	int ret;
+
+	ret = dm_pci_bus_find_bdf(TNC_IGD, &igd);
+	if (ret)
+		return ret;
+	if (!igd)
+		return 0;
+
+	ret = dm_pci_bus_find_bdf(TNC_SDVO, &sdvo);
+	if (ret)
+		return ret;
+	if (!sdvo)
+		return 0;
+
 	/*
 	 * According to Atom E6xx datasheet, setting VGA Disable (bit17)
 	 * of Graphics Controller register (offset 0x50) prevents IGD
@@ -34,8 +51,45 @@ static void __maybe_unused disable_igd(void)
 	 * two devices will be completely disabled (invisible in the PCI
 	 * configuration space) unless a system reset is performed.
 	 */
-	x86_pci_write_config32(TNC_IGD, IGD_FD, FUNC_DISABLE);
-	x86_pci_write_config32(TNC_SDVO, IGD_FD, FUNC_DISABLE);
+	dm_pci_write_config32(igd, IGD_FD, FUNC_DISABLE);
+	dm_pci_write_config32(sdvo, IGD_FD, FUNC_DISABLE);
+
+	/*
+	 * After setting the function disable bit, IGD and SDVO devices will
+	 * disappear in the PCI configuration space. This however creates an
+	 * inconsistent state from a driver model PCI controller point of view,
+	 * as these two PCI devices are still attached to its parent's child
+	 * device list as maintained by the driver model. Some driver model PCI
+	 * APIs like dm_pci_find_class(), are referring to the list to speed up
+	 * the finding process instead of re-enumerating the whole PCI bus, so
+	 * it gets the stale cached data which is wrong.
+	 *
+	 * Note x86 PCI enueration normally happens twice, in pre-relocation
+	 * phase and post-relocation. One option might be to call disable_igd()
+	 * in one of the pre-relocation initialization hooks so that it gets
+	 * disabled in the first round, and when it comes to the second round
+	 * driver model PCI will construct a correct list. Unfortunately this
+	 * does not work as Intel FSP is used on this platform to perform low
+	 * level initialization, and fsp_init_phase_pci() is called only once
+	 * in the post-relocation phase. If we disable IGD and SDVO devices,
+	 * fsp_init_phase_pci() simply hangs and never returns.
+	 *
+	 * So the only option we have is to manually remove these two devices.
+	 */
+	ret = device_remove(igd);
+	if (ret)
+		return ret;
+	ret = device_unbind(igd);
+	if (ret)
+		return ret;
+	ret = device_remove(sdvo);
+	if (ret)
+		return ret;
+	ret = device_unbind(sdvo);
+	if (ret)
+		return ret;
+
+	return 0;
 }
 
 int arch_cpu_init(void)
@@ -53,9 +107,11 @@ int arch_cpu_init(void)
 
 int arch_early_init_r(void)
 {
+	int ret = 0;
+
 #ifdef CONFIG_DISABLE_IGD
-	disable_igd();
+	ret = disable_igd();
 #endif
 
-	return 0;
+	return ret;
 }