drm/radeon/kms: wait for cp idle before stopping it.

If we stop CP and that it's still processing thing GPU hang might
happen, this patch wait for CP idle (the wait can timeout) so we
can avoid shutting down CP at bad time. This is especialy usefull
when reseting the GPU as it seems GPU reset fails to properly reset
CP when the CP wasn't stop after being idle.
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/r100.c

@@ -487,6 +487,21 @@ int r100_copy_blit(struct radeon_device *rdev,
 /*
  * CP
  */
+static int r100_cp_wait_for_idle(struct radeon_device *rdev)
+{
+	unsigned i;
+	u32 tmp;
+
+	for (i = 0; i < rdev->usec_timeout; i++) {
+		tmp = RREG32(R_000E40_RBBM_STATUS);
+		if (!G_000E40_CP_CMDSTRM_BUSY(tmp)) {
+			return 0;
+		}
+		udelay(1);
+	}
+	return -1;
+}
+
 void r100_ring_start(struct radeon_device *rdev)
 {
 	int r;
@@ -715,6 +730,9 @@ int r100_cp_init(struct radeon_device *rdev, unsigned ring_size)
 
 void r100_cp_fini(struct radeon_device *rdev)
 {
+	if (r100_cp_wait_for_idle(rdev)) {
+		DRM_ERROR("Wait for CP idle timeout, shutting down CP.\n");
+	}
 	/* Disable ring */
 	rdev->cp.ready = false;
 	WREG32(RADEON_CP_CSQ_CNTL, 0);

drivers/gpu/drm/radeon/r100d.h

@@ -73,4 +73,64 @@
 #define CP_PACKET0_GET_ONE_REG_WR(h) (((h) >> 15) & 1)
 #define CP_PACKET3_GET_OPCODE(h) (((h) >> 8) & 0xFF)
 
+/* Registers */
+#define R_000E40_RBBM_STATUS                         0x000E40
+#define   S_000E40_CMDFIFO_AVAIL(x)                    (((x) & 0x7F) << 0)
+#define   G_000E40_CMDFIFO_AVAIL(x)                    (((x) >> 0) & 0x7F)
+#define   C_000E40_CMDFIFO_AVAIL                       0xFFFFFF80
+#define   S_000E40_HIRQ_ON_RBB(x)                      (((x) & 0x1) << 8)
+#define   G_000E40_HIRQ_ON_RBB(x)                      (((x) >> 8) & 0x1)
+#define   C_000E40_HIRQ_ON_RBB                         0xFFFFFEFF
+#define   S_000E40_CPRQ_ON_RBB(x)                      (((x) & 0x1) << 9)
+#define   G_000E40_CPRQ_ON_RBB(x)                      (((x) >> 9) & 0x1)
+#define   C_000E40_CPRQ_ON_RBB                         0xFFFFFDFF
+#define   S_000E40_CFRQ_ON_RBB(x)                      (((x) & 0x1) << 10)
+#define   G_000E40_CFRQ_ON_RBB(x)                      (((x) >> 10) & 0x1)
+#define   C_000E40_CFRQ_ON_RBB                         0xFFFFFBFF
+#define   S_000E40_HIRQ_IN_RTBUF(x)                    (((x) & 0x1) << 11)
+#define   G_000E40_HIRQ_IN_RTBUF(x)                    (((x) >> 11) & 0x1)
+#define   C_000E40_HIRQ_IN_RTBUF                       0xFFFFF7FF
+#define   S_000E40_CPRQ_IN_RTBUF(x)                    (((x) & 0x1) << 12)
+#define   G_000E40_CPRQ_IN_RTBUF(x)                    (((x) >> 12) & 0x1)
+#define   C_000E40_CPRQ_IN_RTBUF                       0xFFFFEFFF
+#define   S_000E40_CFRQ_IN_RTBUF(x)                    (((x) & 0x1) << 13)
+#define   G_000E40_CFRQ_IN_RTBUF(x)                    (((x) >> 13) & 0x1)
+#define   C_000E40_CFRQ_IN_RTBUF                       0xFFFFDFFF
+#define   S_000E40_CF_PIPE_BUSY(x)                     (((x) & 0x1) << 14)
+#define   G_000E40_CF_PIPE_BUSY(x)                     (((x) >> 14) & 0x1)
+#define   C_000E40_CF_PIPE_BUSY                        0xFFFFBFFF
+#define   S_000E40_ENG_EV_BUSY(x)                      (((x) & 0x1) << 15)
+#define   G_000E40_ENG_EV_BUSY(x)                      (((x) >> 15) & 0x1)
+#define   C_000E40_ENG_EV_BUSY                         0xFFFF7FFF
+#define   S_000E40_CP_CMDSTRM_BUSY(x)                  (((x) & 0x1) << 16)
+#define   G_000E40_CP_CMDSTRM_BUSY(x)                  (((x) >> 16) & 0x1)
+#define   C_000E40_CP_CMDSTRM_BUSY                     0xFFFEFFFF
+#define   S_000E40_E2_BUSY(x)                          (((x) & 0x1) << 17)
+#define   G_000E40_E2_BUSY(x)                          (((x) >> 17) & 0x1)
+#define   C_000E40_E2_BUSY                             0xFFFDFFFF
+#define   S_000E40_RB2D_BUSY(x)                        (((x) & 0x1) << 18)
+#define   G_000E40_RB2D_BUSY(x)                        (((x) >> 18) & 0x1)
+#define   C_000E40_RB2D_BUSY                           0xFFFBFFFF
+#define   S_000E40_RB3D_BUSY(x)                        (((x) & 0x1) << 19)
+#define   G_000E40_RB3D_BUSY(x)                        (((x) >> 19) & 0x1)
+#define   C_000E40_RB3D_BUSY                           0xFFF7FFFF
+#define   S_000E40_SE_BUSY(x)                          (((x) & 0x1) << 20)
+#define   G_000E40_SE_BUSY(x)                          (((x) >> 20) & 0x1)
+#define   C_000E40_SE_BUSY                             0xFFEFFFFF
+#define   S_000E40_RE_BUSY(x)                          (((x) & 0x1) << 21)
+#define   G_000E40_RE_BUSY(x)                          (((x) >> 21) & 0x1)
+#define   C_000E40_RE_BUSY                             0xFFDFFFFF
+#define   S_000E40_TAM_BUSY(x)                         (((x) & 0x1) << 22)
+#define   G_000E40_TAM_BUSY(x)                         (((x) >> 22) & 0x1)
+#define   C_000E40_TAM_BUSY                            0xFFBFFFFF
+#define   S_000E40_TDM_BUSY(x)                         (((x) & 0x1) << 23)
+#define   G_000E40_TDM_BUSY(x)                         (((x) >> 23) & 0x1)
+#define   C_000E40_TDM_BUSY                            0xFF7FFFFF
+#define   S_000E40_PB_BUSY(x)                          (((x) & 0x1) << 24)
+#define   G_000E40_PB_BUSY(x)                          (((x) >> 24) & 0x1)
+#define   C_000E40_PB_BUSY                             0xFEFFFFFF
+#define   S_000E40_GUI_ACTIVE(x)                       (((x) & 0x1) << 31)
+#define   G_000E40_GUI_ACTIVE(x)                       (((x) >> 31) & 0x1)
+#define   C_000E40_GUI_ACTIVE                          0x7FFFFFFF
+
 #endif