Hi, >> Here is the fresh usbmon trace. Four SCSI commands are shown. The >> first SCSI_READ_10 command has LBA of 0. The second SCSI_READ_10 >> command has LBA of 0x00ed2900, which is wrong. Somehow, the first >> SCSI_READ_10 command got the wrong data, i think. Isn't it? > > It looks like the data is wrong, but I have no way of knowing what the > data actually should be. Only you know that. > >> f31a9740 4037054141 S Bo:2:071:1 -115 31 = 55534243 0c000000 00100000 >> 80000a28 00000000 00000008 00000000 000000 >> f31a9740 4037054176 C Bo:2:071:1 0 31 > >> f4a555c0 4037054184 S Bi:2:071:1 -115 4096 < >> f4a555c0 4037108430 C Bi:2:071:1 0 4096 = eb58904d 53444f53 352e3000 >> 02402e11 02000000 00f80000 3f00ff00 00200000 > > Is this different from what you have in the first 32 bytes of your > backing file? If it is then your UDC driver is not sending the correct > buffer data to the host. The first 32 bytes data is correct. It is the first 32 bytes content of the FAT boot record. I observed further, when first SCSI_READ_10 command is sent with LBA of zero, and the file_offset_tmp of vfs_read() in do_read() is passed in as 0. It reaches SD driver with argument of 0x2002, . Somehow, the address got passed wrongly in the processing of it. In this case, 0x2000 is the FAT boot sector. Shouldn't gadget driver read from MBR (master boot record) as LBA of zero corresponds to MBR? Thanks, victor -- 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
