From 8e04d8056c1ea0e0aab730994b74756f0526cda8 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Fri, 1 Oct 2010 14:20:08 -0700 Subject: 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 --- include/scsi/scsi_device.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/scsi/scsi_device.h') diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 50cb34ffef1..e8c2433ad8a 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 */ -- cgit v1.2.3-70-g09d2 From 5ce524bdff367b4abda20bcfd4dafd9d30c773df Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Fri, 1 Oct 2010 14:20:10 -0700 Subject: scsi/sd: add a no_read_capacity_16 scsi_device flag I seem to have a knack for digging up buggy usb devices which don't work with Linux, and I'm crazy enough to try to make them work. So this time a friend of mine asked me to get an mp4 player (an mp3 player which can play videos on a small screen) to work with Linux. It is based on the well known rockbox chipset for which we already have an unusual devs entries to work around some of its bugs. But this model comes with an additional twist. This model chokes on read_capacity_16 calls. Now normally we don't make those calls, but this model comes with an sdcard slot and when there is no card in there (and shipped from the factory there is none), it reports a size of 0. However this time the programmers actually got the read_capacity_10 response right! So they substract one from the size as stored internally in the mp3 player before reporting it back, resulting in an answer of ... 0xffffffff sectors, causing sd.c to try a read_capacity_16, on which the device crashes. This patch adds a flag to scsi_device to indicate that a a device cannot handle read_capacity_16, and when this flag is set if a device reports an lba of 0xffffffff as answer to a read_capacity_10, assumes it tries to report a size of 0. 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/sd.c | 12 ++++++++++++ include/scsi/scsi_device.h | 1 + 2 files changed, 13 insertions(+) (limited to 'include/scsi/scsi_device.h') diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index ffa0689ee84..ff4c9a3aa5b 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1498,6 +1498,9 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp, unsigned long long lba; unsigned sector_size; + if (sdp->no_read_capacity_16) + return -EINVAL; + do { memset(cmd, 0, 16); cmd[0] = SERVICE_ACTION_IN; @@ -1626,6 +1629,15 @@ static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp, sector_size = get_unaligned_be32(&buffer[4]); lba = get_unaligned_be32(&buffer[0]); + if (sdp->no_read_capacity_16 && (lba == 0xffffffff)) { + /* Some buggy (usb cardreader) devices return an lba of + 0xffffffff when the want to report a size of 0 (with + which they really mean no media is present) */ + sdkp->capacity = 0; + sdkp->hw_sector_size = sector_size; + return sector_size; + } + if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) { sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a " "kernel compiled with support for large block " diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index e8c2433ad8a..85867dcde33 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -149,6 +149,7 @@ struct scsi_device { 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 no_read_capacity_16:1; /* Avoid READ_CAPACITY_16 cmds */ unsigned is_visible:1; /* is the device visible in sysfs */ DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */ -- cgit v1.2.3-70-g09d2