On Mon, Mar 02, 2009 at 02:42:15PM -0500, Alan Stern wrote: > On Mon, 2 Mar 2009, Thadeu Lima de Souza Cascardo wrote: > > > Hello, > > > > Some time ago, I've worked with a Sandisk storage device, which could > > not resume properly. I've found out that it was timing out when > > receiving requests. I could mount it right after resuming, but using a > > mounted device was not possible. Since this device is the only storage > > present in some mobile, it is used as the root device and cannot be > > unmounted. > > > > I've thought this was a bug in the device itself and not a problem in > > the bus or host controller, since other devices worked pretty well. > > After doing some tests, I've realized that doing a rescan in the device > > before accessing it worked. And setting manage_start_stop as true does > > this automatically when resuming for us. > > > > Thus, the patch below. I would like some comments about this particular > > issue and, if the solution is acceptable, I will send a proper commit > > log. > > Maybe there doesn't need to be a patch for this at all. Can't you get > the same result by writing a udev rule? In fact, isn't that how the > manage_start_stop flag is intended to be set? I did expect that doing it in user space would be the proper way. Any tips on how to find out the USB id's given the disk? > As for the patch itself... You are setting the flag in the wrong > place. The manage_start_stop flag applies only to SCSI disk devices > AFAICT. (The sysfs interface isn't present if the device isn't a disk, > at any rate.) So you should set the flag in the code that applies to > disks. I thought on adding a quirk flag to the SCSI host and, then, testing that in the SCSI code itself. Didn't think SCSI guys would like that. > Also, this patch won't apply to the current development tree, because > there have been several changes to usb-storage's recently. In > particular there is new code allowing quirk flags to be set by a module > parameter, and your new flag (if it is accepted) should be added to > this mechanism. Also expected. But I didn't know about the new changes in the quirk flags code. Which tree should I refer to regarding usb-storage or USB, besides next and rc trees? > Alan Stern > Thank you very much for your prompt answer and advice. Regards, Cascardo.
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