Commit b0bcdd3c authored by Jean Delvare's avatar Jean Delvare
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hwmon: (w83781d) Request I/O ports individually for probing

Different motherboards have different PNP declarations for
W83781D/W83782D chips. Some declare the whole range of I/O ports (8
ports), some declare only the useful ports (2 ports at offset 5) and
some declare fancy ranges, for example 4 ports at offset 4. To
properly handle all cases, request all ports individually for probing.
After we have determined that we really have a W83781D or W83782D
chip, the useful port range will be requested again, as a single

I did not see a board which needs this yet, but I know of one for lm78
driver and I'd like to keep the logic of these two drivers in sync.
Signed-off-by: default avatarJean Delvare <>
parent 197027e6
......@@ -1793,17 +1793,17 @@ static int __init
w83781d_isa_found(unsigned short address)
int val, save, found = 0;
/* We have to request the region in two parts because some
boards declare base+4 to base+7 as a PNP device */
if (!request_region(address, 4, "w83781d")) {
pr_debug("w83781d: Failed to request low part of region\n");
return 0;
int port;
/* Some boards declare base+0 to base+7 as a PNP device, some base+4
* to base+7 and some base+5 to base+6. So we better request each port
* individually for the probing phase. */
for (port = address; port < address + W83781D_EXTENT; port++) {
if (!request_region(port, 1, "w83781d")) {
pr_debug("w83781d: Failed to request port 0x%x\n",
goto release;
if (!request_region(address + 4, 4, "w83781d")) {
pr_debug("w83781d: Failed to request high part of region\n");
release_region(address, 4);
return 0;
......@@ -1877,8 +1877,8 @@ w83781d_isa_found(unsigned short address)
val == 0x30 ? "W83782D" : "W83781D", (int)address);
release_region(address + 4, 4);
release_region(address, 4);
for (port--; port >= address; port--)
release_region(port, 1);
return found;
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