Radeon RV250 Lockup

[vehemens <veh...@ve...>]

I've managed to eliminate a number of lockups when running one or more copies 
of glxgears and other GL programs with the patch below.

This suggests that the driver needs some type of command timing/processing 
rules to prevent lockup (NOPs?).

I working on the other lockups, but debug seems to fix the problem which is 
another indicator that the remaining problems are due to timing.

*** drm111605/shared-core/radeon_state.c        Fri Nov 11 20:25:43 2005
--- drmbld/shared-core/radeon_state.c   Wed Nov 23 11:35:29 2005
***************
*** 2737,2742 ****
--- 2737,2743 ----
        drm_radeon_cmd_header_t header;
        int orig_nbox, orig_bufsz;
        char *kbuf = NULL;
+       RING_LOCALS;
  
        LOCK_TEST_WITH_RETURN(dev, filp);
  
***************
*** 2791,2796 ****
--- 2792,2802 ----
                header.i = *(int *)cmdbuf.buf;
                cmdbuf.buf += sizeof(header);
                cmdbuf.bufsz -= sizeof(header);
+ 
+               /* hack */
+               BEGIN_RING(2);
+               RADEON_WAIT_UNTIL_IDLE();
+               ADVANCE_RING();
  
                switch (header.header.cmd_type) {
                case RADEON_CMD_PACKET: