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Diffstat (limited to 'src/mesa/drivers/dri/common/vblank.c')
| -rw-r--r-- | src/mesa/drivers/dri/common/vblank.c | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/common/vblank.c b/src/mesa/drivers/dri/common/vblank.c new file mode 100644 index 00000000000..e91dd65260c --- /dev/null +++ b/src/mesa/drivers/dri/common/vblank.c @@ -0,0 +1,325 @@ +/* -*- mode: c; c-basic-offset: 3 -*- */ +/* + * (c) Copyright IBM Corporation 2002 + * All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * on the rights to use, copy, modify, merge, publish, distribute, sub + * license, and/or sell copies of the Software, and to permit persons to whom + * the Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL + * VA LINUX SYSTEM, IBM AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR + * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE + * USE OR OTHER DEALINGS IN THE SOFTWARE. + * + * Authors: + * Ian Romanick <[email protected]> + */ +/* $XFree86:$ */ + +#include "glheader.h" +#include "xf86drm.h" +#include "mtypes.h" +#include "macros.h" +#include "dd.h" +#include "vblank.h" + + +/****************************************************************************/ +/** + * Get the current MSC refresh counter. + * + * Stores the 64-bit count of vertical refreshes since some (arbitrary) + * point in time in \c count. Unless the value wraps around, which it + * may, it will never decrease. + * + * \warning This function is called from \c glXGetVideoSyncSGI, which expects + * a \c count of type \c unsigned (32-bit), and \c glXGetSyncValuesOML, which + * expects a \c count of type \c int64_t (signed 64-bit). The kernel ioctl + * currently always returns a \c sequence of type \c unsigned. + * + * \param priv Pointer to the DRI screen private struct. + * \param count Storage to hold MSC counter. + * \return Zero is returned on success. A negative errno value + * is returned on failure. + */ +int driGetMSC32( __DRIscreenPrivate * priv, int64_t * count ) +{ + drmVBlank vbl; + int ret; + + /* Don't wait for anything. Just get the current refresh count. */ + + vbl.request.type = DRM_VBLANK_RELATIVE; + vbl.request.sequence = 0; + + ret = drmWaitVBlank( priv->fd, &vbl ); + *count = (int64_t)vbl.reply.sequence; + + return ret; +} + + +/****************************************************************************/ +/** + * Wait for a specified refresh count. This implements most of the + * functionality of \c glXWaitForMscOML from the GLX_OML_sync_control spec. + * Waits for the \c target_msc refresh. If that has already passed, it + * waits until \f$(MSC \bmod divisor)\f$ is equal to \c remainder. If + * \c target_msc is 0, use the behavior of glXWaitVideoSyncSGI(), which + * omits the initial check against a target MSC value. + * + * This function is actually something of a hack. The problem is that, at + * the time of this writing, none of the existing DRM modules support an + * ioctl that returns a 64-bit count (at least not on 32-bit platforms). + * However, this function exists to support a GLX function that requires + * the use of 64-bit counts. As such, there is a little bit of ugly + * hackery at the end of this function to make the 32-bit count act like + * a 64-bit count. There are still some cases where this will break, but + * I believe it catches the most common cases. + * + * The real solution is to provide an ioctl that uses a 64-bit count. + * + * \param dpy Pointer to the \c Display. + * \param priv Pointer to the DRI drawable private. + * \param target_msc Desired refresh count to wait for. A value of 0 + * means to use the glXWaitVideoSyncSGI() behavior. + * \param divisor MSC divisor if \c target_msc is already reached. + * \param remainder Desired MSC remainder if \c target_msc is already + * reached. + * \param msc Buffer to hold MSC when done waiting. + * + * \return Zero on success or \c GLX_BAD_CONTEXT on failure. + */ + +int driWaitForMSC32( __DRIdrawablePrivate *priv, + int64_t target_msc, int64_t divisor, int64_t remainder, + int64_t * msc ) +{ + drmVBlank vbl; + + + if ( divisor != 0 ) { + unsigned int target = (unsigned int)target_msc; + unsigned int next = target; + unsigned int r; + int dont_wait = (target_msc == 0); + + do { + /* dont_wait means we're using the glXWaitVideoSyncSGI() behavior. + * The first time around, just get the current count and proceed + * to the test for (MSC % divisor) == remainder. + */ + vbl.request.type = dont_wait ? DRM_VBLANK_RELATIVE : + DRM_VBLANK_ABSOLUTE; + vbl.request.sequence = next; + + if ( drmWaitVBlank( priv->driScreenPriv->fd, &vbl ) != 0 ) { + /* FIXME: This doesn't seem like the right thing to return here. + */ +#ifndef _SOLO + return GLX_BAD_CONTEXT; +#else + return -1; +#endif + } + + dont_wait = 0; + if (target_msc != 0 && vbl.reply.sequence == target) + break; + + /* Assuming the wait-done test fails, the next refresh to wait for + * will be one that satisfies (MSC % divisor) == remainder. The + * value (MSC - (MSC % divisor) + remainder) is the refresh value + * closest to the current value that would satisfy the equation. + * If this refresh has already happened, we add divisor to obtain + * the next refresh after the current one that will satisfy it. + */ + r = (vbl.reply.sequence % (unsigned int)divisor); + next = (vbl.reply.sequence - r + (unsigned int)remainder); + if (next <= vbl.reply.sequence) next += (unsigned int)divisor; + + } while ( r != (unsigned int)remainder ); + } + else { + /* If the \c divisor is zero, just wait until the MSC is greater + * than or equal to \c target_msc. + */ + + vbl.request.type = DRM_VBLANK_ABSOLUTE; + vbl.request.sequence = target_msc; + + if ( drmWaitVBlank( priv->driScreenPriv->fd, &vbl ) != 0 ) { + /* FIXME: This doesn't seem like the right thing to return here. + */ +#ifndef _SOLO + return GLX_BAD_CONTEXT; +#else + return -1; +#endif + } + } + + *msc = (target_msc & 0xffffffff00000000LL); + *msc |= vbl.reply.sequence; + if ( *msc < target_msc ) { + *msc += 0x0000000100000000LL; + } + + return 0; +} + + +/****************************************************************************/ +/** + * Gets a set of default vertical-blank-wait flags based on the internal GLX + * API version and several environment variables. + */ + +GLuint driGetDefaultVBlankFlags( void ) +{ + GLuint flags = 0; + + + flags |= (driCompareGLXAPIVersion( 20030317 ) >= 0) + ? VBLANK_FLAG_INTERVAL : 0; + flags |= (getenv("LIBGL_SYNC_REFRESH") != NULL) + ? VBLANK_FLAG_SYNC : 0; + flags |= (getenv("LIBGL_THROTTLE_REFRESH") != NULL) + ? VBLANK_FLAG_THROTTLE : 0; + + return flags; +} + + +/****************************************************************************/ +/** + * Wrapper to call \c drmWaitVBlank. The main purpose of this function is to + * wrap the error message logging. The error message should only be logged + * the first time the \c drmWaitVBlank fails. If \c drmWaitVBlank is + * successful, \c vbl_seq will be set the sequence value in the reply. + * + * \param vbl Pointer to drmVBlank packet desribing how to wait. + * \param vbl_seq Location to store the current refresh counter. + * \param fd File descriptor use to call into the DRM. + * \return Zero on success or -1 on failure. + */ + +static int do_wait( drmVBlank * vbl, GLuint * vbl_seq, int fd ) +{ + int ret; + + + ret = drmWaitVBlank( fd, vbl ); + if ( ret != 0 ) { + static GLboolean first_time = GL_TRUE; + + if ( first_time ) { + fprintf(stderr, + "%s: drmWaitVBlank returned %d, IRQs don't seem to be" + " working correctly.\nTry running with LIBGL_THROTTLE_REFRESH" + " and LIBL_SYNC_REFRESH unset.\n", __FUNCTION__, ret); + first_time = GL_FALSE; + } + + return -1; + } + + *vbl_seq = vbl->reply.sequence; + return 0; +} + + +/****************************************************************************/ +/** + * Waits for the vertical blank for use with glXSwapBuffers. + * + * \param vbl_seq Vertical blank sequence number (MSC) after the last buffer + * swap. Updated after this wait. + * \param flags \c VBLANK_FLAG bits that control how long to wait. + * \param missed_deadline Set to \c GL_TRUE if the MSC after waiting is later + * than the "target" based on \c flags. The idea is that if + * \c missed_deadline is set, then the application is not + * achieving its desired framerate. + * \return Zero on success, -1 on error. + */ + +int +driWaitForVBlank( const __DRIdrawablePrivate *priv, GLuint * vbl_seq, + GLuint flags, GLboolean * missed_deadline ) +{ + drmVBlank vbl; + unsigned original_seq; + unsigned deadline; + unsigned interval; + + + *missed_deadline = GL_FALSE; + if ( (flags & VBLANK_FLAG_NO_IRQ) != 0 ) { + return 0; + } + + + /* VBLANK_FLAG_SYNC means to wait for at least one vertical blank. If + * that flag is not set, do a fake wait for zero vertical blanking + * periods so that we can get the current MSC. + * + * VBLANK_FLAG_INTERVAL and VBLANK_FLAG_THROTTLE mean to wait for at + * least one vertical blank since the last wait. Since do_wait modifies + * vbl_seq, we have to save the original value of vbl_seq for the + * VBLANK_FLAG_INTERVAL / VBLANK_FLAG_THROTTLE calculation later. + */ + + original_seq = *vbl_seq; + + vbl.request.sequence = ((flags & VBLANK_FLAG_SYNC) != 0) ? 1 : 0; + vbl.request.type = DRM_VBLANK_RELATIVE; + + if ( do_wait( & vbl, vbl_seq, priv->driScreenPriv->fd ) != 0 ) { + return -1; + } + + + vbl.request.type = DRM_VBLANK_ABSOLUTE; + + if ( (flags & VBLANK_FLAG_INTERVAL) != 0 ) { +#ifndef _SOLO + interval = priv->pdraw->swap_interval; +#else + interval = 0; +#endif + } + else if ( (flags & VBLANK_FLAG_THROTTLE) != 0 ) { + interval = 1; + } + else { + interval = 0; + } + + + /* Wait until the next vertical blank. If the interval is zero, then + * the deadline is one vertical blank after the previous wait. + */ + + vbl.request.sequence = original_seq + interval; + if ( *vbl_seq < vbl.request.sequence ) { + if ( do_wait( & vbl, vbl_seq, priv->driScreenPriv->fd ) != 0 ) { + return -1; + } + } + + deadline = original_seq + ((interval == 0) ? 1 : interval); + *missed_deadline = ( *vbl_seq > deadline ); + + return 0; +} |