Sound: adding /proc/driver/{vendor}/{dev_pci}/ac97 entry for es1371 driver

Kernel: 2.4.17
Hardware: CT5880+Sigmatel Codec
Module: sound/es1371.c

The following patch adds a proc entry to fetch information about the codec attached to the CT5880 (ES137x) chip.
Note: Most of the code is already in ac97_codec.c module.

Doubts:
1) This adds something like: /proc/driver/es1371/00:03.00/ac97 I took the idea from emu10k1.c module. My doubt is about the `:' it looks wrong in a file name, specially when that's usually used to separate file names/paths. Should we pass it by a small routine that converts : into something like _?
2) I used a buffer of fixed length as in other modules, but I don't feel really good doing it. What solutions are recommended? (if any)

diff -ru linux-2.4.17.ori/drivers/sound/es1371.c
linux-2.4.17/drivers/sound/es1371.c

@@ -110,6 +110,8 @@
  *    31.01.2001   0.30  Register/Unregister gameport
  *                       Fix SETTRIGGER non OSS API conformity
  *    14.07.2001   0.31  Add list of laptops needing amplifier control
+ *    08.01.2002   0.32  Add /proc/driver/es1371/{card}/ac97 entry
+ *                       Salvador E. Tropea <[email protected]>
  */
 
 /*****************************************************************************/

@@ -2803,6 +2805,7 @@

        unsigned long tmo;
        signed long tmo2;
        unsigned int cssr;

+ char proc_str[80];

        if ((res=pci_enable_device(pcidev)))
                return res;
@@ -2960,6 +2963,16 @@
        for (i = 0; i < sizeof(initvol)/sizeof(initvol[0]); i++) {
                val = initvol[i].vol;
                mixdev_ioctl(&s->codec, initvol[i].mixch, (unsigned
long)&val);
+       }
+
+       /* create a proc entry to inform about the codec facilities */
+       strcpy(proc_str, "driver/es1371");
+       if (proc_mkdir (proc_str, 0)) {

+ sprintf(proc_str, "driver/es1371/%s", s->dev->slot_name);
+ if (proc_mkdir (proc_str, 0)) {
+ strcat(proc_str, "/ac97");
+ create_proc_read_entry(proc_str, 0, 0,
ac97_read_proc, &s->codec);
+ }

        }
        /* mute master and PCM when in S/PDIF mode */
        if (s->spdif_volume != -1) {

<--------End of patch

--
Salvador Eduardo Tropea (SET). (Electronics Engineer) Visit my home page: http://welcome.to/SetSoft or
http://www.geocities.com/SiliconValley/Vista/6552/
Alternative e-mail: [email protected] [email protected]
Address: Curapaligue 2124, Caseros, 3 de Febrero Buenos Aires, (1678), ARGENTINA Phone: +(5411) 4759 0013

Uttered "salvador" <[email protected]>, spoke thus:

I wouldn't change it. In fact, Linux allows _any_ character except a NULL in a filename, although POSIX doesn't. (Well, I wouldn't use a '/' in a filename even if I escaped it out the wazoo!)

The kernel stack is really small and doesn't grow, so a buffer allocated on the stack could cause "load-dependent instability". Using a "vmalloc" and a "vfree" is fast, cheap and easy.

-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- + -- -- -- -- -- -- -- -- -- --
Tommy Reynolds                               | mailto: <[email protected]>
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