From 8e04d8056c1ea0e0aab730994b74756f0526cda8 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Fri, 1 Oct 2010 14:20:08 -0700 Subject: [PATCH] scsi/sr: add no_read_disc_info scsi_device flag Some USB devices emulate a usb-mass-storage attached (scsi) cdrom device, usually this fake cdrom contains the windows software for the device. While working on supporting Appotech ax3003 based photoframes, which do this I discovered that they will go of into lala land when ever they see a READ_DISC_INFO scsi command. Thus this patch adds a scsi_device flag (which can then be set by the usb-storage driver through an unsual-devs entry), to indicate this, and makes the sr driver honor this flag. I know this sucks, but as discussed on linux-scsi list there is no other way to make this device work properly. Looking at usb traces made under windows, windows never sends a READ_DISC_INFO during normal interactions with a usb cdrom device. So as this cdrom emulation thingie becomes more common we might see more of this problem. Signed-off-by: Hans de Goede Cc: James Bottomley Cc: Alan Stern Cc: Matthew Dharm Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/sr.c | 8 +++++++- include/scsi/scsi_device.h | 1 + 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index ba9c3e0387ce..b811dd0eb240 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -862,10 +862,16 @@ static void get_capabilities(struct scsi_cd *cd) static int sr_packet(struct cdrom_device_info *cdi, struct packet_command *cgc) { + struct scsi_cd *cd = cdi->handle; + struct scsi_device *sdev = cd->device; + + if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info) + return -EDRIVE_CANT_DO_THIS; + if (cgc->timeout <= 0) cgc->timeout = IOCTL_TIMEOUT; - sr_do_ioctl(cdi->handle, cgc); + sr_do_ioctl(cd, cgc); return cgc->stat; } diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 50cb34ffef11..e8c2433ad8a8 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -148,6 +148,7 @@ struct scsi_device { unsigned retry_hwerror:1; /* Retry HARDWARE_ERROR */ unsigned last_sector_bug:1; /* do not use multisector accesses on SD_LAST_BUGGY_SECTORS */ + unsigned no_read_disc_info:1; /* Avoid READ_DISC_INFO cmds */ unsigned is_visible:1; /* is the device visible in sysfs */ DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */ -- 2.20.1