Attachment 124492 Details for Bug 96500 – Proposed IGA1 CrtcHTotal limit test mistake fix

[patch] Proposed IGA1 CrtcHTotal limit test mistake fix

IGA1_CrtcHTotal_Limit_Test_Mistake_Fix.patch (text/plain), 1.25 KB, created by Kevin Brace on 2016-06-13 07:01:24 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Kevin Brace

Created: 2016-06-13 07:01:24 UTC

Size: 1.25 KB

patch

obsolete

>diff --git a/src/via_display.c b/src/via_display.c
>index e58d7dc..476d0d8 100644
>--- a/src/via_display.c
>+++ b/src/via_display.c
>@@ -1222,18 +1222,7 @@ viaIGA1ModeValid(ScrnInfoPtr pScrn, DisplayModePtr mode)
>     DEBUG(xf86DrvMsg(pScrn->scrnIndex, X_INFO,
>                         "Entered viaIGA1ModeValid.\n"));
> 
>-    /* Note that horizontal total being written to VGA registers is
>-     * shifted to the right by 3 bit positions, and then 5 is subtracted
>-     * from it. Hence, to check if the screen can even be valid,
>-     * opposite of that needs to happen. That being said, to check if the
>-     * number is within an acceptable range, 1 is subtracted from 5, hence,
>-     * 4 (5 - 1) is multiplied with 8 (i.e., 1 is shifted 3 bit positions to
>-     * the left) and the resulting 32 is added to 2048 to calculate the
>-     * maximum horizontal total IGA1 can handle. Ultimately, 2080 is the
>-     * largest number VIA IGP's IGA1 can handle safely. This is how
>-     * VIA Technologies gets to claim that IGA1 (i.e., VGA) is capable of
>-     * 1920 dots in the horizontal (Y) direction. */
>-    if (mode->CrtcHTotal > (2048 + ((1 << 3) * 4)))
>+    if (mode->CrtcHTotal > (4096 + ((1 << 3) * (5 - 1)))
>         return MODE_BAD_HVALUE;
> 
>     if (mode->CrtcHDisplay > 2048)

Actions: View | Splinter Review

Attachments on bug 96500: 124489 | 124490 | 124492

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.