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authorLijo Lazar <lijo.lazar@amd.com>2024-04-12 13:11:14 +0530
committerAlex Deucher <alexander.deucher@amd.com>2024-04-23 23:23:45 -0400
commit30d1cda8ce31ab49051ff7159280c542a738b23d (patch)
treeecfb9542ad8da3fa7db0ea05efb7d36bedb8a8c3
parent661d71ee5a010bdc0663e0db701931aff920e8e1 (diff)
downloadlinux-30d1cda8ce31ab49051ff7159280c542a738b23d.tar.gz
drm/amd/pm: Restore config space after reset
During mode-2 reset, pci config space registers are affected at device side. However, certain platforms have switches which assign virtual BAR addresses and returns the same even after device is reset. This affects pci_restore_state() as it doesn't issue another config write, if the value read is same as the saved value. Add a workaround to write saved config space values from driver side. Presently, these switches are in platforms with SMU v13.0.6 SOCs, hence restrict the workaround only to those. Signed-off-by: Lijo Lazar <lijo.lazar@amd.com> Reviewed-by: Asad Kamal <asad.kamal@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
-rw-r--r--drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c
index 3957af057d54ff..c977ebe88001df 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c
@@ -2294,6 +2294,17 @@ static ssize_t smu_v13_0_6_get_gpu_metrics(struct smu_context *smu, void **table
return sizeof(*gpu_metrics);
}
+static void smu_v13_0_6_restore_pci_config(struct smu_context *smu)
+{
+ struct amdgpu_device *adev = smu->adev;
+ int i;
+
+ for (i = 0; i < 16; i++)
+ pci_write_config_dword(adev->pdev, i * 4,
+ adev->pdev->saved_config_space[i]);
+ pci_restore_msi_state(adev->pdev);
+}
+
static int smu_v13_0_6_mode2_reset(struct smu_context *smu)
{
int ret = 0, index;
@@ -2315,6 +2326,20 @@ static int smu_v13_0_6_mode2_reset(struct smu_context *smu)
/* Restore the config space saved during init */
amdgpu_device_load_pci_state(adev->pdev);
+ /* Certain platforms have switches which assign virtual BAR values to
+ * devices. OS uses the virtual BAR values and device behind the switch
+ * is assgined another BAR value. When device's config space registers
+ * are queried, switch returns the virtual BAR values. When mode-2 reset
+ * is performed, switch is unaware of it, and will continue to return
+ * the same virtual values to the OS.This affects
+ * pci_restore_config_space() API as it doesn't write the value saved if
+ * the current value read from config space is the same as what is
+ * saved. As a workaround, make sure the config space is restored
+ * always.
+ */
+ if (!(adev->flags & AMD_IS_APU))
+ smu_v13_0_6_restore_pci_config(smu);
+
dev_dbg(smu->adev->dev, "wait for reset ack\n");
do {
ret = smu_cmn_wait_for_response(smu);