Re: writable mmc profiles actually are writable

Pat LaVarre
2003-10-06T20:58:32Z

> patches to make the detection more modern ...

Below appears a copy of an old patch to try op x46 get_configuration any
time mode page x2a doesn't already say the pdt x05 dvd/cd device is
writable.

> I'd propose just adding better detection of
> new devices, and adding a specific "randomly
> writable" flag instead of abusing CDC_DVD_RAM.

Ah, did that, see below. With this remark to motivate me, I will rev
this -test5 patch to fit with -test6 and then repost.

> I haven't yet had to deal with dvd+rw or
> ddcd_rw (is this like mtr?

Sorry I do not know mtr.

> mo and dvd-ram have been supported for a long
> time and should be set with CDC_DVD_RAM,

Sorry I do not understand. I remember noticing CDC_MO_DRIVE appears
only drivers/ide/ not in drivers/scsi/. Weakly I conclude mo doesn't
work the same in atapi and usb-storage.

> the disk profiles aren't driven by ide-cd or
> sr.

Sorry I do not understand.

In drivers/scsi/sr.c I find:
cd->cdi.mask |= CDC_DVD_RAM;

In drivers/ide/ide-cd.c I find:
devinfo->mask |= CDC_DVD_RAM;

I conclude sr and ide-cd tell cdrom whether the device "profile" is
writable or not. Is that wrong?

> you should have done

Thanks again for finding the time to clue me in.

Pat LaVarre

diff -Nur linux-2.6.0-test5/include/scsi/scsi.h linux/include/scsi/scsi.h
diff -Nur linux-2.6.0-test5/include/linux/cdrom.h linux/include/linux/cdrom.h
diff -Nur linux-2.6.0-test5/drivers/cdrom/cdrom.c linux/drivers/cdrom/cdrom.c
diff -Nur linux-2.6.0-test5/drivers/scsi/sr.c linux/drivers/scsi/sr.c
--- linux-2.6.0-test5/include/scsi/scsi.h 2003-09-08 13:50:41.000000000 -0600
+++ linux/include/scsi/scsi.h 2003-09-10 17:05:37.000000000 -0600
@@ -81,6 +81,7 @@
#define CHANGE_DEFINITION 0x40
#define WRITE_SAME 0x41
#define READ_TOC 0x43
+#define GET_CONFIGURATION 0x46
#define LOG_SELECT 0x4c
#define LOG_SENSE 0x4d
#define MODE_SELECT_10 0x55
--- linux-2.6.0-test5/include/linux/cdrom.h 2003-09-08 13:49:51.000000000 -0600
+++ linux/include/linux/cdrom.h 2003-09-10 17:05:37.000000000 -0600
@@ -388,6 +388,7 @@
#define CDC_DVD_R 0x10000 /* drive can write DVD-R */
#define CDC_DVD_RAM 0x20000 /* drive can write DVD-RAM */
#define CDC_MO_DRIVE 0x40000 /* drive is an MO device */
+#define CDC_MMC_RW 0x80000 /* drive is other mmc "writable" "profile" */

/* drive status possibilities returned by CDROM_DRIVE_STATUS ioctl */
#define CDS_NO_INFO 0 /* if not implemented */
--- linux-2.6.0-test5/drivers/cdrom/cdrom.c 2003-09-08 13:49:53.000000000 -0600
+++ linux/drivers/cdrom/cdrom.c 2003-09-10 17:05:37.000000000 -0600
@@ -426,7 +426,7 @@
if ((fp->f_flags & O_NONBLOCK) && (cdi->options & CDO_USE_FFLAGS))
ret = cdi->ops->open(cdi, 1);
else {
- if ((fp->f_mode & FMODE_WRITE) && !CDROM_CAN(CDC_DVD_RAM))
+ if ((fp->f_mode & FMODE_WRITE) && !CDROM_CAN(CDC_DVD_RAM|CDC_MMC_RW))
return -EROFS;

ret = open_for_data(cdi);
@@ -2456,6 +2456,10 @@
for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_DVD_RAM) != 0);

+ pos += sprintf(info+pos, "\nCan write other MMC-RW:");
+ for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
+ pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_MMC_RW) != 0);
+
strcpy(info+pos,"\n\n");

return proc_dostring(ctl, write, filp, buffer, lenp);
--- linux-2.6.0-test5/drivers/scsi/sr.c 2003-09-08 13:49:58.000000000 -0600
+++ linux/drivers/scsi/sr.c 2003-09-10 17:13:08.000000000 -0600
@@ -67,7 +67,8 @@
(CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \
CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \
CDC_PLAY_AUDIO|CDC_RESET|CDC_IOCTLS|CDC_DRIVE_STATUS| \
- CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET)
+ CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
+ CDC_MMC_RW)

static int sr_probe(struct device *);
static int sr_remove(struct device *);
@@ -92,6 +93,10 @@
static void get_sectorsize(struct scsi_cd *);
static void get_capabilities(struct scsi_cd *);

+static void get_configuration(struct scsi_cd *);
+static int scsi_get_configuration(struct scsi_device *sdev,
+ unsigned char *buffer, int len, int timeout, int retries);
+
static int sr_media_change(struct cdrom_device_info *, int);
static int sr_packet(struct cdrom_device_info *, struct cdrom_generic_command *);

@@ -755,6 +760,7 @@
rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
SR_TIMEOUT, 3, &data);

+ cd->cdi.mask |= CDC_MMC_RW;
if (!scsi_status_is_good(rc)) {
/* failed, drive doesn't have capabilities mode page */
cd->cdi.speed = 1;
@@ -817,6 +823,83 @@

scsi_release_request(SRpnt);
kfree(buffer);
+
+ if (!cd->device->writeable) {
+ printk("%s: scsi3-mmc maybe not writeable\n",
+ cd->cdi.name);
+ get_configuration(cd);
+ }
+}
+
+static void get_configuration(struct scsi_cd *cd)
+{
+ unsigned char *buffer;
+ int rc, mmc_profile;
+
+ buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
+ if (!buffer) {
+ printk(KERN_ERR "sr: out of memory.\n");
+ return;
+ }
+
+ rc = scsi_get_configuration(cd->device, buffer, 8,
+ SR_TIMEOUT, 1);
+ if (!scsi_status_is_good(rc)) {
+ kfree(buffer);
+ return;
+ }
+
+ mmc_profile = ((buffer[6] << 8) + buffer[7]);
+ switch (mmc_profile) {
+ case 0x0001: /* Non-Removable Disk */
+ case 0x0002: /* Removable Disk */
+ case 0x0003: /* Magneto-Optical Erasable */
+ case 0x0005: /* AS-MO */
+ case 0x0012: /* DVD-RAM */
+ case 0x001A: /* DVD+RW */
+ case 0x0022: /* DDCD-RW */
+ printk("%s: scsi3-mmc writable profile: 0x%04x\n",
+ cd->cdi.name, mmc_profile);
+ cd->device->writeable = 1;
+ if (mmc_profile != 0x001A) { /* != DVD+RW */
+ cd->cdi.mask &= ~CDC_MMC_RW;
+ }
+ break;
+ default:
+ break;
+ }
+
+ kfree(buffer);
+}
+
+/* intended to be block-copy-edit of scsi.lib.c scsi_mode_sense */
+static int
+scsi_get_configuration(struct scsi_device *sdev,
+ unsigned char *buffer, int len, int timeout, int retries)
+{
+ struct scsi_request *sreq = scsi_allocate_request(sdev, GFP_KERNEL);
+ unsigned char cmd[MAX_COMMAND_SIZE];
+ int ret;
+
+ if (!sreq)
+ return -1;
+
+ memset(&cmd[0], 0, MAX_COMMAND_SIZE);
+ cmd[0] = GET_CONFIGURATION;
+ cmd[8] = len;
+
+ sreq->sr_cmd_len = 0;
+ sreq->sr_sense_buffer[0] = 0;
+ sreq->sr_sense_buffer[2] = 0;
+ sreq->sr_data_direction = DMA_FROM_DEVICE;
+
+ memset(buffer, 0, len);
+
+ scsi_wait_req(sreq, cmd, buffer, len, timeout, retries);
+
+ ret = sreq->sr_result;
+ scsi_release_request(sreq);
+ return ret;
}

/*