From: Adam Belay <ambx1@neo.rr.com>
Some isapnp devices were not getting detected as a result of a bug in the
isapnp driver. It was not following the specifications and calculating a
checksum when it was not reliable. This problem was originally discovered by
Paul L. Rogers <rogerspl@datasync.com>. He made an initial patch. This
release has some small modifications, including a check to see if we run out
of CSNs.
---
25-akpm/drivers/pnp/isapnp/core.c | 14 ++++++--------
1 files changed, 6 insertions(+), 8 deletions(-)
diff -puN drivers/pnp/isapnp/core.c~pnp-03-fix-device-detection drivers/pnp/isapnp/core.c
--- 25/drivers/pnp/isapnp/core.c~pnp-03-fix-device-detection 2004-03-14 23:58:06.843840776 -0800
+++ 25-akpm/drivers/pnp/isapnp/core.c 2004-03-14 23:58:06.846840320 -0800
@@ -99,6 +99,7 @@ MODULE_LICENSE("GPL");
static unsigned char isapnp_checksum_value;
static DECLARE_MUTEX(isapnp_cfg_mutex);
static int isapnp_detected;
+static int isapnp_csn_count;
/* some prototypes */
@@ -371,11 +372,14 @@ static int __init isapnp_isolate(void)
break;
}
__next:
+ if (csn == 255)
+ break;
checksum = 0x6a;
chksum = 0x00;
bit = 0x00;
}
isapnp_wait();
+ isapnp_csn_count = csn;
return csn;
}
@@ -880,7 +884,7 @@ static int __init isapnp_build_device_li
isapnp_wait();
isapnp_key();
- for (csn = 1; csn <= 10; csn++) {
+ for (csn = 1; csn <= isapnp_csn_count; csn++) {
isapnp_wake(csn);
isapnp_peek(header, 9);
checksum = isapnp_checksum(header);
@@ -890,12 +894,6 @@ static int __init isapnp_build_device_li
header[4], header[5], header[6], header[7], header[8]);
printk(KERN_DEBUG "checksum = 0x%x\n", checksum);
#endif
- /* Don't be strict on the checksum, here !
- e.g. 'SCM SwapBox Plug and Play' has header[8]==0 (should be: b7)*/
- if (header[8] == 0)
- ;
- else if (checksum == 0x00 || checksum != header[8]) /* not valid CSN */
- continue;
if ((card = isapnp_alloc(sizeof(struct pnp_card))) == NULL)
continue;
@@ -932,7 +930,7 @@ int isapnp_present(void)
int isapnp_cfg_begin(int csn, int logdev)
{
- if (csn < 1 || csn > 10 || logdev > 10)
+ if (csn < 1 || csn > isapnp_csn_count || logdev > 10)
return -EINVAL;
MOD_INC_USE_COUNT;
down(&isapnp_cfg_mutex);
_