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cdrom: support read sub-channel command in LBA format

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userspace application can send READ_SUB_CHANNEL command with time bit
enabled and disabled. The time bit allows selection of address reporting
format. If the time bit is disabled the response is in logical block
address(CDROM_LBA) format, represented as a 32-bit integer with ms-byte
first. If the time bit is enabled the response is in time format i.e.,
minutes, second, frame (CDROM_MSF) format.

Signed-off-by: vchannaiah <vanitha.channaiah@in.bosch.com>
Signed-off-by: Mahendran Kuppusamy <mahendran.kuppusamy@in.bosch.com>
[veeraiyan.chidambaram@in.bosch.com: updated Documentation/ioctl/cdrom.txt]
Signed-off-by: Veeraiyan Chidambaram <veeraiyan.chidambaram@in.bosch.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
vchannaiah 2016-06-29 08:18:25 -04:00 committed by Jens Axboe
parent 54adc01055
commit bf294e833b
2 changed files with 21 additions and 10 deletions
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3
Documentation/ioctl/cdrom.txt
View file

@ -340,7 +340,8 @@ CDROMSUBCHNL Read subchannel data (struct cdrom_subchnl)
EINVAL format not CDROM_MSF or CDROM_LBA
notes:
Format is converted to CDROM_MSF on return
Format is converted to CDROM_MSF or CDROM_LBA
as per user request on return

28
drivers/cdrom/cdrom.c
View file

@ -2032,7 +2032,7 @@ static int cdrom_read_subchannel(struct cdrom_device_info *cdi,
init_cdrom_command(&cgc, buffer, 16, CGC_DATA_READ);
cgc.cmd[0] = GPCMD_READ_SUBCHANNEL;
cgc.cmd[1] = 2; /* MSF addressing */
cgc.cmd[1] = subchnl->cdsc_format;/* MSF or LBA addressing */
cgc.cmd[2] = 0x40; /* request subQ data */
cgc.cmd[3] = mcn ? 2 : 1;
cgc.cmd[8] = 16;
@ -2041,17 +2041,27 @@ static int cdrom_read_subchannel(struct cdrom_device_info *cdi,
return ret;
subchnl->cdsc_audiostatus = cgc.buffer[1];
subchnl->cdsc_format = CDROM_MSF;
subchnl->cdsc_ctrl = cgc.buffer[5] & 0xf;
subchnl->cdsc_trk = cgc.buffer[6];
subchnl->cdsc_ind = cgc.buffer[7];
subchnl->cdsc_reladdr.msf.minute = cgc.buffer[13];
subchnl->cdsc_reladdr.msf.second = cgc.buffer[14];
subchnl->cdsc_reladdr.msf.frame = cgc.buffer[15];
subchnl->cdsc_absaddr.msf.minute = cgc.buffer[9];
subchnl->cdsc_absaddr.msf.second = cgc.buffer[10];
subchnl->cdsc_absaddr.msf.frame = cgc.buffer[11];
if (subchnl->cdsc_format == CDROM_LBA) {
subchnl->cdsc_absaddr.lba = ((cgc.buffer[8] << 24) |
(cgc.buffer[9] << 16) |
(cgc.buffer[10] << 8) |
(cgc.buffer[11]));
subchnl->cdsc_reladdr.lba = ((cgc.buffer[12] << 24) |
(cgc.buffer[13] << 16) |
(cgc.buffer[14] << 8) |
(cgc.buffer[15]));
} else {
subchnl->cdsc_reladdr.msf.minute = cgc.buffer[13];
subchnl->cdsc_reladdr.msf.second = cgc.buffer[14];
subchnl->cdsc_reladdr.msf.frame = cgc.buffer[15];
subchnl->cdsc_absaddr.msf.minute = cgc.buffer[9];
subchnl->cdsc_absaddr.msf.second = cgc.buffer[10];
subchnl->cdsc_absaddr.msf.frame = cgc.buffer[11];
}
return 0;
}
@ -3022,7 +3032,7 @@ static noinline int mmc_ioctl_cdrom_subchannel(struct cdrom_device_info *cdi,
if (!((requested == CDROM_MSF) ||
(requested == CDROM_LBA)))
return -EINVAL;
q.cdsc_format = CDROM_MSF;
ret = cdrom_read_subchannel(cdi, &q, 0);
if (ret)
return ret;