Your link isn't really valid in this context. The logical equivalence
applies to singular bits, not to a multibit value.
0x10 & 0x01 evaluates to 0x00 (== false), while 0x10 && 0x01 evaluates to
0x01 (a true value).
Those switch statements will always end up in cases 0 or 1.
Further, logical operators && and || are lazy, while bitwise operators &
and | are not.
Regards,
Mario.
2016-06-21 0:30 GMT-03:00 Kevin Brace <kevinbr...@gmx.com>:
> Hi Xavier,
>
> >
> > Signed-off-by: Xavier Bachelot <xav...@bachelot.org>
> > ---
> > src/via_outputs.c | 24 ++++++++++++------------
> > 1 file changed, 12 insertions(+), 12 deletions(-)
> >
> > diff --git a/src/via_outputs.c b/src/via_outputs.c
> > index 7e21e8c..30602dd 100644
> > --- a/src/via_outputs.c
> > +++ b/src/via_outputs.c
> > @@ -1045,7 +1045,7 @@ viaProbePinStrapping(ScrnInfoPtr pScrn)
> > /* 3C5.12[4] - FPD17 pin strapping
> > * 0: TMDS transmitter (DVI) / capture device
> > * 1: Flat panel */
> > - if (sr12 && 0x10) {
> > + if (sr12 & 0x10) {
> > xf86DrvMsg(pScrn->scrnIndex, X_INFO,
> > "A flat panel is connected to "
> > "flat panel interface.\n");
> > @@ -1065,7 +1065,7 @@ viaProbePinStrapping(ScrnInfoPtr pScrn)
> > /* 3C5.12[5] - FPD18 pin strapping
> > * 0: TMDS transmitter (DVI)
> > * 1: TV encoder */
> > - if (sr12 && 0x20) {
> > + if (sr12 & 0x20) {
> > xf86DrvMsg(pScrn->scrnIndex, X_INFO,
> > "A TMDS transmitter (DVI) is connected to "
> > "DVI port.\n");
> > @@ -1079,17 +1079,17 @@ viaProbePinStrapping(ScrnInfoPtr pScrn)
> > * 01: NTSC
> > * 10: PAL-N
> > * 11: PAL-NC */
> > - if (sr13 && 0x04) {
> > + if (sr13 & 0x04) {
> > xf86DrvMsg(pScrn->scrnIndex, X_INFO,
> > "NTSC for the TV encoder.\n");
> > } else {
> > - if (!(sr13 && 0x08)) {
> > + if (!(sr13 & 0x08)) {
> > xf86DrvMsg(pScrn->scrnIndex, X_INFO,
> > "PAL for the TV encoder.\n");
> > } else {
> > xf86DrvMsg(pScrn->scrnIndex, X_INFO,
> > "PAL%s for the TV encoder.\n",
> > - sr13 && 0x04 ? "-NC" : "-N");
> > + sr13 & 0x04 ? "-NC" : "-N");
> > }
> > }
> > @@ -1098,7 +1098,7 @@ viaProbePinStrapping(ScrnInfoPtr pScrn)
> > * 1: 625 lines (PAL) */
> > xf86DrvMsg(pScrn->scrnIndex, X_INFO,
> > "%s lines for the TV encoder.\n",
> > - sr12 && 0x40 ? "625" : "525");
> > + sr12 & 0x40 ? "625" : "525");
> > }
> > break;
> > @@ -1112,12 +1112,12 @@ viaProbePinStrapping(ScrnInfoPtr pScrn)
> > * DVI or TV out use
> > * 1: Enable DVP0 (Digital Video Port 0) for
> > * DVI or TV out use */
> > - if (sr12 && 0x40) {
> > + if (sr12 & 0x40) {
> > /* 3C5.12[5] - DVP0D5 pin strapping
> > * 0: TMDS transmitter (DVI)
> > * 1: TV encoder */
> > - if (sr12 && 0x20) {
> > + if (sr12 & 0x20) {
> > xf86DrvMsg(pScrn->scrnIndex, X_INFO,
> > "A TV encoder is detected on "
> > "DVP0 (Digital Video Port 0).\n");
> > @@ -1133,12 +1133,12 @@ viaProbePinStrapping(ScrnInfoPtr pScrn)
> > * 0: AGP pins are used for AGP
> > * 1: AGP pins are used by FPDP
> > * (Flat Panel Display Port) */
> > - if (sr13 && 0x08) {
> > + if (sr13 & 0x08) {
> > /* 3C5.12[4] - DVP0D4 pin strapping
> > * 0: Dual 12-bit FPDP (Flat Panel Display Port)
> > * 1: 24-bit FPDP (Flat Panel Display Port) */
> > - if (sr12 && 0x10) {
> > + if (sr12 & 0x10) {
> > xf86DrvMsg(pScrn->scrnIndex, X_INFO,
> > "24-bit FPDP (Flat Panel Display Port) "
> > "detected.\n");
> > @@ -1159,7 +1159,7 @@ viaProbePinStrapping(ScrnInfoPtr pScrn)
> > * 3C5.12[5] - DVP0D5 pin strapping
> > * 0: TMDS transmitter (DVI)
> > * 1: TV encoder */
> > - if ((!(sr12 && 0x40)) && (!(sr12 && 0x20))) {
> > + if ((!(sr12 & 0x40)) && (!(sr12 & 0x20))) {
> > xf86DrvMsg(pScrn->scrnIndex, X_INFO,
> > "A TV encoder is connected to "
> > "FPDP (Flat Panel Display Port).\n");
> > @@ -1206,7 +1206,7 @@ viaProbePinStrapping(ScrnInfoPtr pScrn)
> > * 01: DVI + LVDS2
> > * 10: Dual LVDS Channel (High Resolution Panel)
> > * 11: One DVI only (decrease the clock jitter) */
> > - switch (sr13 && 0xC0) {
> > + switch (sr13 & 0xC0) {
> > case 0x00:
> > xf86DrvMsg(pScrn->scrnIndex, X_INFO,
> > "LVDS1 + LVDS2 detected.\n");
> > --
> > 2.5.5
> >
> >
>
>
> I am rejecting the inclusion of the patch.
> See the below website.
>
> https://en.wikipedia.org/wiki/Bitwise_operations_in_C#Logical_equivalents
>
> I handled the matter correctly.
>
> Regards,
>
> Kevin Brace
> _______________________________________________
> Openchrome-devel mailing list
> Openchrome-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/openchrome-devel
>
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