Hello, I am a developer of the Rockbox project and I am facing an issue related to how medium are handled in SCSI. I don't know if this is a Rockbox and/or kernel issue, or just a mistunderstanding of the specification. I tried with many kernel version between 2.6.38 and 3.11. I have a device with a micro-sd port and which get reported as a removable LUN. If the micro-sd is initially inserted, TEST UNIT READY will report Good and the kernel will probe capacity and everything works. If I remove the micro-sd (without ejecting on the host before), nothing happen until the host tries to read/write at which point it will: - on old kernel versions: error out and mark the medium as not present - on recent kernel versions: error out, notify capacity change to 0 and mark medium as not present Here is my first question: the old kernel versions used to send TEST UNIT READY all the time, so why isn't the media change notified until I actually try to read/write it ? On newer kernel versions, TEST UNIT READY is only sent before read/write, why was this behaviour changed (and when ?) and has the kernel any way to get notified immediately on eject ? At that point, if I insert my micro-sd again, nothing happen on the host side, both on old and recent kernels, no capacity change, no medium change. If I try to read/write, I always get a "No medium present" error even though the medium is present. This is puzzling for two reasons: - on old kernel versions: since the kernel sends TEST UNIT READY all the time, is has the capacity to detect insertion when LUN becomes Good again ? - on recent kernel versions: since TEST UNIT READY is not sent and the scsi layer somehow caches the medium state, is there any way for the kernel to actually detect that the medium is back ? Finally I should note that this behaviour is not Rockbox specific, even with the vendor implementation of Mass Storage, this problem arises. I am thus wondering if this the expected behaviour, because the device reports the LUN as removable so I assumed that removable meant both remove and insert ! Thanks for your time Amaury Pouly -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
