Hi Alan, On Mon, Feb 11, 2019 at 5:28 PM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > On Mon, 11 Feb 2019, Martin Townsend wrote: > > > Hi, > > > > I've been trying to find a way of informing user space that the eject > > button has been pressed on the host PC. I put some debug in > > do_scsi_command and I only see the TEST_UNIT_READY command with > > nothing in it to distinguish it from other TEST_UNIT_READY commands. > > After loading the gadget kernel module with removable=y I then see > > commands with id 0x03 Request Sense but reading up on this I can't see > > how this would help either. > > The host computer should send a START-STOP command when it wants to > eject the media. > > > Is there anywhere else in the mass storage gadget code that is called > > when the media has been ejected event occurs. > > fsg_lun_close(). That routine gets called from do_start_stop() when an > eject event occurs. (It also gets called from some other places in > other circumstances, such as when the gadget driver is unloaded.) > > > Failing that is there > > any other way I could poll something something from userspace say is > > sysfs that could be used to detect that the host has finished with the > > backing file/eject media has occurred. > > No, that's pretty much it. > > Alan Stern > > > Many Thanks in advance, > > Martin. > I can confirm that do_start_stop is called and the code where it closes the LUN captures the EJECT (tested using Linux and Windows host). up_read(&common->filesem); down_write(&common->filesem); printk(KERN_ERR "do_start_stop -> fsg_lun_close (EJECT)\n"); fsg_lun_close(curlun); up_write(&common->filesem); down_read(&common->filesem); Thank you very much for this as we were about to abandon MSG :) I have one more problem, if I specify removable=y I can't re-insert the device and after reading the documentation it looks like I have to reset the backing file attribute in sysfs but I can't seem to write to the file attribute: root@beeker:/sys/module/g_mass_storage/parameters# ls -la total 0 drwxr-xr-x 2 root root 0 Feb 4 19:16 . drwxr-xr-x 6 root root 0 Feb 4 19:15 .. -r--r--r-- 1 root root 4096 Feb 4 19:16 bcdDevice -r--r--r-- 1 root root 4096 Feb 4 19:16 cdrom -r--r--r-- 1 root root 4096 Feb 4 19:16 file -r--r--r-- 1 root root 4096 Feb 4 19:16 iManufacturer -r--r--r-- 1 root root 4096 Feb 4 19:16 iProduct -r--r--r-- 1 root root 4096 Feb 4 19:16 iSerialNumber -r--r--r-- 1 root root 4096 Feb 4 19:16 idProduct -r--r--r-- 1 root root 4096 Feb 4 19:16 idVendor -r--r--r-- 1 root root 4096 Feb 4 19:16 luns -r--r--r-- 1 root root 4096 Feb 4 19:16 nofua -r--r--r-- 1 root root 4096 Feb 4 19:16 removable -r--r--r-- 1 root root 4096 Feb 4 19:16 ro -r--r--r-- 1 root root 4096 Feb 4 19:16 stall Even if I set the file to writable I just get an IO error. root@beeker:/sys/module/g_mass_storage/parameters# chmod 666 file root@beeker:/sys/module/g_mass_storage/parameters# echo /data/mass_storage/msg.bin > file -sh: echo: write error: Input/output error Any ideas as to why I'm seeing this? If I remove and reinsert the g_mass_storage gadget kernel module I can re-insert the device. I would like to build the gadget driver into the kernel as mass storage is the only gadget function we have and I believe it can be built into the kernel if this is the case. Thanks Again, Martin.
