diff options
| -rw-r--r-- | sys/src/9/pc/sdide.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/sys/src/9/pc/sdide.c b/sys/src/9/pc/sdide.c index 24ff84015..1ab4fe8e5 100644 --- a/sys/src/9/pc/sdide.c +++ b/sys/src/9/pc/sdide.c @@ -549,7 +549,7 @@ atadmamode(SDunit *unit, Drive* drive) static int ataidentify(Ctlr*, int cmdport, int ctlport, int dev, int pkt, void* info) { - int as, command, drdy; + int as, command, drdy, rlo, rhi; if(pkt){ command = Cidpkt; @@ -561,8 +561,21 @@ ataidentify(Ctlr*, int cmdport, int ctlport, int dev, int pkt, void* info) } dev &= ~Lba; as = ataready(cmdport, ctlport, dev, Bsy|Drq, drdy, 103*1000); - if(as < 0) - return as; + if(as < 0){ + /* try to detect floating bus */ + outb(cmdport+Cyllo, 0xAA); + outb(cmdport+Cylhi, 0x55); + outb(cmdport+Sector, 0xFF); + rlo = inb(cmdport+Cyllo); + rhi = inb(cmdport+Cylhi); + if(rlo != 0xAA && (rlo == 0xFF || rhi != 0x55)) + return as; + + /* theres a device, try waiting some more */ + as = ataready(cmdport, ctlport, dev, Bsy|Drq, drdy, 6*1000*1000); + if(as < 0) + return as; + } outb(cmdport+Command, command); microdelay(1); |