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nusb/usbd: use per hname collision counter instead of device address to resolve collisions

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The device address is highly variable and depends on
all prior enumerated devices.

This can happen with some devices that do not have
a serial number and all devices of the same type
having the same hname.

Using a counter of collisions per hname makes more sense
and is more stable (given that the order devices are
enumerated is deterministic).
This commit is contained in:
cinap_lenrek 2022-02-06 01:19:01 +00:00
parent fc0357b3de
commit 4ab2d149d4
3 changed files with 14 additions and 10 deletions
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2
sys/src/cmd/nusb/usbd/fns.h
View file

@ -2,5 +2,5 @@ int attachdev(Port*);
void detachdev(Port*);
void work(void);
Hub* newhub(char *, Dev*);
void hname(char *);
int hname(char *);
void checkidle(void);

4
sys/src/cmd/nusb/usbd/hname.c
View file

@ -3,7 +3,7 @@
#include <mp.h>
#include <libsec.h>
void
int
hname(char *buf)
{
uchar d[SHA1dlen];
@ -13,5 +13,5 @@ hname(char *buf)
n = strlen(buf);
sha1((uchar*)buf, n, d, nil);
x = d[0] | d[1]<<8 | d[2]<<16;
snprint(buf, n+1, "%.5ux", x & 0xfffff);
return snprint(buf, n+1, "%.5ux", x & 0xfffff);
}

16
sys/src/cmd/nusb/usbd/usbd.c
View file

@ -363,7 +363,8 @@ assignhname(Dev *dev)
char buf[64];
Usbdev *ud;
Hub *h;
int i;
int col;
int i, n;
ud = dev->usb;
@ -371,22 +372,25 @@ assignhname(Dev *dev)
snprint(buf, sizeof(buf), "%.4x%.4x%.4x%.6lx%s",
ud->vid, ud->did, ud->dno, ud->csp, ud->serial);
hname(buf);
n = hname(buf);
/* check for collisions */
col = 0;
for(h = hubs; h != nil; h = h->next){
for(i = 1; i <= h->nport; i++){
if(h->port[i].dev == nil)
continue;
if(h->port[i].dev->hname == nil || h->port[i].dev == dev)
continue;
if(strcmp(h->port[i].dev->hname, buf) == 0){
dev->hname = smprint("%s%d", buf, dev->id);
return;
}
if(strncmp(h->port[i].dev->hname, buf, n) == 0)
col++;
}
}
if(col == 0)
dev->hname = strdup(buf);
else
dev->hname = smprint("%s%d", buf, col);
}
int