2011/10/18 yingchun li <sword.l.dragon@xxxxxxxxx>: > On Wed, Oct 12, 2011 at 9:36 AM, Barry Song <Baohua.Song@xxxxxxx> wrote: >> From: YuPing Luo <yuping.luo@xxxxxxx> >> >> With Peiyu's patch "gadget: mass_storage: adapt logic block size to bound block >> devices" (http://www.spinics.net/lists/linux-usb/msg50791.html), now mass storage >> can adjust logic block size dynamically based on real devices. >> Then there is one issue caused by it, if two luns have different logic block size, >> mass storage can't work. >> Let's check the current software flow: >> 1. get_next_command(): call received_cbw(); >> 2. received_cbw(): update common->lun = cbw->Lun, but common->curlen is not updated; >> 3. do_scsi_command(): in READ_X and WRITE_X commands, common->data_size_from_cmnd is >> updated by common->curlun->blkbits; >> 4. check_command(): update common->curlun according to common->lun >> As you can see, the step 3 uses wrong common->curlun, then wrong common->curlun->blkbits. >> If the two luns have same blkbits, there isn't issue. Otherwise, both will fail. >> This patch moves the common->curlun update to step 2(received_cbw()), then make sure >> step 3 gets right blkbits and right data_size_from_cmnd. >> >> Cc: Peiyu Li <peiyu.li@xxxxxxx> >> Signed-off-by: YuPing Luo <yuping.luo@xxxxxxx> >> Signed-off-by: Barry Song <Baohua.Song@xxxxxxx> >> --- >> drivers/usb/gadget/f_mass_storage.c | 20 +++++++++++++++++--- >> drivers/usb/gadget/file_storage.c | 20 ++++++++++++++++++-- >> 2 files changed, 35 insertions(+), 5 deletions(-) > > Does this mean usb mass storage gadget can be uses as CDROM and disk > simutaneously? I wan't to export two media to PC, one is normal usb-disk, > one is CDROM. not sure it can work now. but definitely this patch makes the driver closer to what you want. you might test, if fail, you send patch. > > Br, > yingchun -barry -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
