Some more quirks for the SM712.

* Program the MCLK to 157MHz on startup.
* Adjust the requested pixel clock if it's near one of the known
  stable frequencies.
* Prefer the clock alternative with post scalar turned on when the
  denominator is even.

3 files changed, 69 insertions, 14 deletions

diff --git a/src/smi_dac.c b/src/smi_dac.c
index f72c77e..de4d794 100644
--- a/src/smi_dac.c
+++ b/src/smi_dac.c
@@ -92,9 +92,20 @@ SMI_CommonCalcClock(int scrnIndex, long freq, int min_m, int min_n1,
 	  best_m, best_n1, best_n2);
 
     if (SMI_LYNX_SERIES(pSmi->Chipset)) {
-	*ndiv = best_n1 | (best_n2 << 6);
+	/* Prefer post scalar enabled for even denominators */
+	if (freq < 70000 && max_n2 > 0 &&
+	    best_n2 == 0 && best_n1 % 2 == 0){
+	    best_n1 >>= 1;
+	    best_n2 = 1;
+	}
+
+	*ndiv = best_n1 |
+	    (best_n2 & 0x1) << 7 |
+	    (best_n2 & 0x2) >> 1 <<6;
     } else {
 	*ndiv = best_n1 | (best_n2 << 7);
+
+	/* Enable second VCO */
 	if (freq > 120000)
 	    *ndiv |= 1 << 6;
     }
diff --git a/src/smi_driver.c b/src/smi_driver.c
index 79d8a0c..12b618f 100644
--- a/src/smi_driver.c
+++ b/src/smi_driver.c
@@ -1222,14 +1222,24 @@ SMI_DetectMCLK(ScrnInfoPtr pScrn)
     int			mclk, mxclk;
     SMIPtr		pSmi = SMIPTR(pScrn);
 
-    pSmi->MCLK = pSmi->MXCLK = 0;
+    /* MCLK defaults */
+    if (pSmi->Chipset == SMI_LYNXEMplus){
+	/* The SM712 can be safely clocked up to 157MHz, according to
+	   Silicon Motion engineers. */
+	pSmi->MCLK = 157000;
+    }else
+	pSmi->MCLK = 0;
+
+    pSmi->MXCLK = 0;
+
+    /* MCLK from user settings */
     if (xf86GetOptValFreq(pSmi->Options, OPTION_MCLK, OPTUNITS_MHZ, &real)) {
-	pSmi->MCLK = (int)(real * 1000.0);
-	if (!IS_MSOC(pSmi) && pSmi->MCLK > 120000) {
+	if (IS_MSOC(pSmi) || (int)real <= 120) {
+	    pSmi->MCLK = (int)(real * 1000.0);
+	} else {
 	    xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
 		       "Memory Clock %1.3f MHz larger than limit of 120 MHz\n",
 		       real);
-	    pSmi->MCLK = 0;
 	}
     }
     mclk = pSmi->MCLK;
@@ -1243,6 +1253,7 @@ SMI_DetectMCLK(ScrnInfoPtr pScrn)
 	}
     }
 
+    /* Already programmed MCLK */
     if (pSmi->MCLK == 0) {
 	if (IS_MSOC(pSmi))
 	    mclk = ((clock.f.m_select ? 336 : 288) /
diff --git a/src/smilynx_crtc.c b/src/smilynx_crtc.c
index 508184f..e5963ff 100644
--- a/src/smilynx_crtc.c
+++ b/src/smilynx_crtc.c
@@ -227,6 +227,34 @@ SMILynx_CrtcAdjustFrame(xf86CrtcPtr crtc, int x, int y)
     LEAVE();
 }
 
+static Bool
+SMILynx_CrtcModeFixup(xf86CrtcPtr crtc,
+		      DisplayModePtr mode,
+		      DisplayModePtr adjusted_mode)
+{
+    ScrnInfoPtr pScrn=crtc->scrn;
+    SMIPtr pSmi = SMIPTR(pScrn);
+
+    ENTER();
+
+    if (pSmi->Chipset == SMI_LYNXEMplus) {
+	/* Adjust the pixel clock in case it is near one of the known
+	   stable frequencies (KHz) */
+	int stable_clocks[] = {46534,};
+	int epsilon = 2000;
+	int i;
+
+	for (i=0; i < sizeof(stable_clocks)/sizeof(int); i++) {
+	    if ( abs(mode->Clock - stable_clocks[i]) < epsilon) {
+		adjusted_mode->Clock = stable_clocks[i];
+		break;
+	    }
+	}
+    }
+
+    LEAVE(TRUE);
+}
+
 static void
 SMILynx_CrtcModeSet_vga(xf86CrtcPtr crtc,
 	    DisplayModePtr mode,
@@ -254,13 +282,13 @@ SMILynx_CrtcModeSet_vga(xf86CrtcPtr crtc,
 
     /* calculate vclk1 */
     if (SMI_LYNX_SERIES(pSmi->Chipset)) {
-        SMI_CommonCalcClock(pScrn->scrnIndex, mode->Clock,
+        SMI_CommonCalcClock(pScrn->scrnIndex, adjusted_mode->Clock,
 			1, 1, 63, 0, 3,
                         pSmi->clockRange.minClock,
                         pSmi->clockRange.maxClock,
                         &reg->SR6C, &reg->SR6D);
     } else {
-        SMI_CommonCalcClock(pScrn->scrnIndex, mode->Clock,
+        SMI_CommonCalcClock(pScrn->scrnIndex, adjusted_mode->Clock,
 			1, 1, 63, 0, 1,
                         pSmi->clockRange.minClock,
                         pSmi->clockRange.maxClock,
@@ -348,13 +376,13 @@ SMILynx_CrtcModeSet_crt(xf86CrtcPtr crtc,
 
     /* calculate vclk1 */
     if (SMI_LYNX_SERIES(pSmi->Chipset)) {
-        SMI_CommonCalcClock(pScrn->scrnIndex, mode->Clock,
+        SMI_CommonCalcClock(pScrn->scrnIndex, adjusted_mode->Clock,
 			1, 1, 63, 0, 3,
                         pSmi->clockRange.minClock,
                         pSmi->clockRange.maxClock,
                         &reg->SR6C, &reg->SR6D);
     } else {
-        SMI_CommonCalcClock(pScrn->scrnIndex, mode->Clock,
+        SMI_CommonCalcClock(pScrn->scrnIndex, adjusted_mode->Clock,
 			1, 1, 63, 0, 1,
                         pSmi->clockRange.minClock,
                         pSmi->clockRange.maxClock,
@@ -456,19 +484,20 @@ SMILynx_CrtcModeSet_lcd(xf86CrtcPtr crtc,
     /* Program the PLL */
 
     /* calculate vclk2 */
-    if (pSmi->Chipset == SMI_LYNX3DM) {
-        SMI_CommonCalcClock(pScrn->scrnIndex, mode->Clock,
-			1, 1, 63, 0, 1,
+    if (SMI_LYNX_SERIES(pSmi->Chipset)) {
+        SMI_CommonCalcClock(pScrn->scrnIndex, adjusted_mode->Clock,
+			1, 1, 63, 0, 0,
                         pSmi->clockRange.minClock,
                         pSmi->clockRange.maxClock,
                         &reg->SR6E, &reg->SR6F);
     } else {
-        SMI_CommonCalcClock(pScrn->scrnIndex, mode->Clock,
-			1, 1, 63, 0, 0,
+        SMI_CommonCalcClock(pScrn->scrnIndex, adjusted_mode->Clock,
+			1, 1, 63, 0, 1,
                         pSmi->clockRange.minClock,
                         pSmi->clockRange.maxClock,
                         &reg->SR6E, &reg->SR6F);
     }
+
     VGAOUT8_INDEX(pSmi, VGA_SEQ_INDEX, VGA_SEQ_DATA, 0x6E, reg->SR6E);
     VGAOUT8_INDEX(pSmi, VGA_SEQ_INDEX, VGA_SEQ_DATA, 0x6F, reg->SR6F);
 
@@ -866,6 +895,7 @@ SMILynx_CrtcPreInit(ScrnInfoPtr pScrn)
 	    crtcFuncs->mode_set = SMILynx_CrtcModeSet_vga;
 	}
 
+	crtcFuncs->mode_fixup = SMILynx_CrtcModeFixup;
 	crtcPriv->adjust_frame = SMILynx_CrtcAdjustFrame;
 	crtcPriv->video_init = SMI730_CrtcVideoInit;
 	crtcPriv->load_lut = SMILynx_CrtcLoadLUT_crt;
@@ -886,6 +916,7 @@ SMILynx_CrtcPreInit(ScrnInfoPtr pScrn)
 	    /* CRTC is LCD*/
 	    SMI_CrtcFuncsInit_base(&crtcFuncs, &crtcPriv);
 	    crtcFuncs->mode_set = SMILynx_CrtcModeSet_lcd;
+	    crtcFuncs->mode_fixup = SMILynx_CrtcModeFixup;
 	    crtcPriv->adjust_frame = SMILynx_CrtcAdjustFrame;
 	    crtcPriv->video_init = SMILynx_CrtcVideoInit_lcd;
 	    crtcPriv->load_lut = SMILynx_CrtcLoadLUT_lcd;
@@ -898,6 +929,7 @@ SMILynx_CrtcPreInit(ScrnInfoPtr pScrn)
 	    SMI_CrtcFuncsInit_base(&crtcFuncs, &crtcPriv);
 	    crtcFuncs->dpms = SMILynx_CrtcDPMS_crt;
 	    crtcFuncs->mode_set = SMILynx_CrtcModeSet_crt;
+	    crtcFuncs->mode_fixup = SMILynx_CrtcModeFixup;
 	    crtcPriv->adjust_frame = SMILynx_CrtcAdjustFrame;
 	    crtcPriv->video_init = SMILynx_CrtcVideoInit_crt;
 	    crtcPriv->load_lut = SMILynx_CrtcLoadLUT_crt;
@@ -918,6 +950,7 @@ SMILynx_CrtcPreInit(ScrnInfoPtr pScrn)
 		crtcFuncs->mode_set = SMILynx_CrtcModeSet_vga;
 	    }
 
+	    crtcFuncs->mode_fixup = SMILynx_CrtcModeFixup;
 	    crtcPriv->adjust_frame = SMILynx_CrtcAdjustFrame;
 	    crtcPriv->video_init = SMILynx_CrtcVideoInit_crt;
 	    crtcPriv->load_lut = SMILynx_CrtcLoadLUT_crt;