On Tue, Mar 14, 2006 at 03:29:44PM +0300, Sergey Vlasov wrote:
> On Mon, 13 Mar 2006 17:26:44 -0500 Bill Nottingham wrote:
>
> > Kay Sievers ([email protected]) said:
> > > > See:
> > > > https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=178998
>
> I have written a comment in that bugzilla entry, but it is probably too
> terse, so I'll try to explain the problem and my proposed solution
> better.
>
> > > > This doesn't work for everything.
> > >
> > > Sure not, and I don't think "everything" in PnP will ever work. :) But
> > > it does the same as the modalias patch to the kernel we are talking about.
> > > There are device table entries completely missing and some other don't
> > > match. Some of them can be fixed by adding the aliases as modprobe.conf
> > > entries.
> >
> > Well, it's just that if this is the solution proposed, I'd like it if
> > it worked for any of the people who are seeing problems - in our bugs,
> > it hasn't helped any of them yet.
>
> There are two kinds of PNP drivers:
>
> 1) PNP device drivers, which use struct pnp_driver. These drivers use
> struct pnp_device_id in id_table entries; struct pnp_device_id
> contains a single device ID field which is used for matching.
> Aliases for these drivers have the form:
>
> pnp:dXXXYYYY*
>
> where XXXYYYY is the PNP ID which is matched.
>
> 2) PNP card drivers, which use struct pnp_card_driver. These drivers
> use struct pnp_card_device_id in id_table entries; struct
> pnp_card_device_id contains ID for the card itself and a variable
> number of logical device IDs. drivers/pnp/card.c:match_card() uses
> these rules for matching struct pnp_card_device_id to a device:
>
> a) the card IDs must match;
> b) all device IDs mentioned in struct pnp_card_device_id must be
> present in the card, but can be in any order (and there may be
> more devices than listed in the ID table).
>
> Aliases for card drivers currently have the form:
>
> pnp:cXXXYYYYdXXXYYYYdXXXYYYY*
>
> The first "cXXXYYYY" part is the card ID, and "dXXXYYYY" parts are
> device IDs (there may be up to PNP_MAX_DEVICES == 8 of them).
>
> Now, for the drivers of the first type the only problem is that the
> devices can have several compatible IDs in addition to the primary ID,
> and this requires either a multiline "modalias" attribute, or a helper
> script to call modprobe multiple times with the pnp:dXXXYYYY alias for
> all available IDs.
>
> Drivers of the second type - PNP card drivers - are only used for isapnp
> (pnpbios and pnpacpi have only plain devices). Cards itself have only a
> single ID (there are no compatible IDs for cards), but every logical
> device on a card can have up to DEVICE_COUNT_COMPATIBLE == 4 compatible
> IDs in addition to the primary ID.
>
> (BTW, #define DEVICE_COUNT_COMPATIBLE 4 is duplicated in <linux/pci.h>
> and <linux/isapnp.h> - if these values were different, it would be a
> nasty bug.)
>
> For the card drivers, in addition to the problem with compatible IDs, we
> have another problem - the alias format for them is wrong! The problem
> is that if device IDs in the alias happen to be in a different order
> than the same IDs in the actual device (or even in the same order, but
> some devices are not mentioned in the ID table), fnmatch() used by
> modprobe will not match this alias.
>
> To solve this problem, I suggest to do this:
>
> 1) Change the alias format for PNP card drivers to require logical
> device IDs to be sorted, and add an "*" before every device ID part.
> The alias format becomes:
>
> pnp:cXXXYYYY*dXXXYYYY*dXXXYYYY*
>
> 2) Update scripts/mod/file2alias.c:do_pnp_card_entry() to write the new
> alias format (it should sort device IDs - no need to change all
> drivers to list device IDs in sorted order and create potential for
> bugs when someone adds a non-sorted entry).
>
> 3) Update /etc/udev/isapnp script mentioned in bugzilla entry to sort
> device ID values before concatenating them.
>
> After dust settles, we can then add "modalias" attribute generation for
> PNP card devices to the kernel - note that this attribute would have
> only a single value which would list the card ID and all (primary and
> compatible) IDs of all logical devices in sorted order.
>
> BTW, we can change the alias format for PNP device drivers to
>
> pnp:*dXXXYYYY*
>
> (note the additional "*" before the device ID). This would allow us to
> have a single-value "modalias" attribute for PNP logical devices too -
> it would have the form
>
> pnp:dXXXYYYYdXXXYYYYdXXXYYYY
>
> (listing all IDs, in this case sorting is not required, because each
> driver will match at most only a single dXXXYYYY entry).
Hi all,
Sorry for the long quotation, but I think you might have forgotten what
this thread was about.
Basically I implemented the above things, to be precise:
- the alias for the pnp device drivers are in the form "pnp:*dXXXYYYY*"
instead of the old "pnp:dXXXYYYY*"
- the alias for the pnp card drivers are in the form
"pnp:cXXXYYYY*dXXXYYYY*dXXXYYYY*"
instead of the old
"pnp:cXXXYYYYdXXXYYYYdXXXYYYY*"
_and_ the device id part are ordered
- add a "modalias" file under sysfs for each pnp device, containing
"pnp:dXXXYYYYdXXXYYYY..."
where "dXXXYYYY" is appended for each pnp id the device has
- add a "modalias" file under sysfs for each pnp card, containing
"pnp:cXXXYYYYdXXXYYYYdXXXYYYY..."
where "cXXXYYYY" is the card_id, and the device ids are appended
after it, _ordered_.
With this applied, I think we are close to be able to drop
special-casing the pnp bus in udev rules.
What still needs to be done is exporting the MODALIAS env variable.
(Sorry, I do not see how it could be added elegantly.)
Please tell me what you think of it.
thanks,
pozsy
diff -urd a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
--- a/scripts/mod/file2alias.c 2006-05-02 23:38:44.000000000 +0200
+++ b/scripts/mod/file2alias.c 2006-05-08 21:57:33.000000000 +0200
@@ -273,21 +273,31 @@
static int do_pnp_entry(const char *filename,
struct pnp_device_id *id, char *alias)
{
- sprintf(alias, "pnp:d%s", id->id);
+ sprintf(alias, "pnp:*d%s", id->id);
return 1;
}
+static int _compare_pnp_id(const void *a, const void *b)
+{
+ const char *aa = a;
+ const char *bb = b;
+ return strcmp(aa, bb);
+}
+
/* looks like: "pnp:cCdD..." */
static int do_pnp_card_entry(const char *filename,
struct pnp_card_device_id *id, char *alias)
{
- int i;
+ int i, j;
sprintf(alias, "pnp:c%s", id->id);
- for (i = 0; i < PNP_MAX_DEVICES; i++) {
- if (! *id->devs[i].id)
- break;
- sprintf(alias + strlen(alias), "d%s", id->devs[i].id);
+ for (j = 0; j < PNP_MAX_DEVICES; j++) {
+ if (! *id->devs[j].id)
+ break;
+ }
+ qsort(id->devs, j, sizeof(id->devs[0]), _compare_pnp_id);
+ for (i = 0; i < j; i++) {
+ sprintf(alias + strlen(alias), "*d%s", id->devs[i].id);
}
return 1;
}
diff -Naurd a/drivers/pnp/card.c b/drivers/pnp/card.c
--- a/drivers/pnp/card.c 2006-05-02 23:38:44.000000000 +0200
+++ b/drivers/pnp/card.c 2006-05-09 19:25:08.000000000 +0200
@@ -8,6 +8,7 @@
#include <linux/config.h>
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/sort.h>
#include <linux/pnp.h>
#include "base.h"
@@ -159,10 +160,34 @@
static DEVICE_ATTR(card_id,S_IRUGO,pnp_show_card_ids,NULL);
+static ssize_t pnp_card_modalias_show(struct device *dmdev, struct device_attribute *attr, char *buf)
+{
+ char *str = buf;
+ struct pnp_card *card = to_pnp_card(dmdev);
+ struct pnp_id * pos = card->id;
+ struct pnp_dev *dev;
+ int i, count = 0;
+ char ids[PNP_MAX_DEVICES][PNP_ID_LEN];
+
+ card_for_each_dev(card, dev) {
+ strcpy(&ids[count++], dev->id);
+ }
+ sort(ids, count, PNP_ID_LEN, strcmp, NULL);
+ str += sprintf(str, "pnp:c%s", pos->id);
+ for (i = 0; i < count; i++) {
+ str += sprintf(str, "d%s", ids[i]);
+ }
+ str += sprintf(str, "\n");
+ return (str - buf);
+}
+
+static DEVICE_ATTR(modalias,S_IRUGO,pnp_card_modalias_show,NULL);
+
static int pnp_interface_attach_card(struct pnp_card *card)
{
device_create_file(&card->dev,&dev_attr_name);
device_create_file(&card->dev,&dev_attr_card_id);
+ device_create_file(&card->dev,&dev_attr_modalias);
return 0;
}
diff -Naurd a/drivers/pnp/interface.c b/drivers/pnp/interface.c
--- a/drivers/pnp/interface.c 2006-05-02 23:38:44.000000000 +0200
+++ b/drivers/pnp/interface.c 2006-05-09 19:25:08.000000000 +0200
@@ -459,10 +459,28 @@
static DEVICE_ATTR(id,S_IRUGO,pnp_show_current_ids,NULL);
+static ssize_t pnp_modalias_show(struct device *dmdev, struct device_attribute *attr, char *buf)
+{
+ char *str = buf;
+ struct pnp_dev *dev = to_pnp_dev(dmdev);
+ struct pnp_id * pos = dev->id;
+
+ str += sprintf(str, "pnp:");
+ while (pos) {
+ str += sprintf(str,"d%s", pos->id);
+ pos = pos->next;
+ }
+ str += sprintf(str, "\n");
+ return (str - buf);
+}
+
+static DEVICE_ATTR(modalias,S_IRUGO,pnp_modalias_show,NULL);
+
int pnp_interface_attach_device(struct pnp_dev *dev)
{
device_create_file(&dev->dev,&dev_attr_options);
device_create_file(&dev->dev,&dev_attr_resources);
device_create_file(&dev->dev,&dev_attr_id);
+ device_create_file(&dev->dev,&dev_attr_modalias);
return 0;
}
--
pozsy
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