From 23c2606ce095279d696b999c5e54d48dd9e0385a Mon Sep 17 00:00:00 2001
From: Norman Feske <norman.feske@genode-labs.com>
Date: Fri, 9 Aug 2019 10:54:31 +0200
Subject: [PATCH] usb_block: support iomega zip drives

This patch enhances the initialization sequence by issueing a START_STOP
SCSI command when needed.

Fixes #3469
---
 repos/os/src/drivers/usb_block/cbw_csw.h | 17 +++++++++++
 repos/os/src/drivers/usb_block/main.cc   | 37 +++++++++++++++++++++---
 repos/os/src/drivers/usb_block/scsi.h    |  2 +-
 3 files changed, 51 insertions(+), 5 deletions(-)

diff --git a/repos/os/src/drivers/usb_block/cbw_csw.h b/repos/os/src/drivers/usb_block/cbw_csw.h
index 55f90ddd87..6c87f2a5e1 100644
--- a/repos/os/src/drivers/usb_block/cbw_csw.h
+++ b/repos/os/src/drivers/usb_block/cbw_csw.h
@@ -105,6 +105,23 @@ struct Request_sense : Usb::Cbw, Scsi::Request_sense
 };
 
 
+struct Start_stop : Usb::Cbw, Scsi::Start_stop
+{
+	Start_stop(addr_t addr, uint32_t tag, uint8_t lun)
+	:
+		Cbw(addr, tag, 0, Usb::ENDPOINT_IN, lun, Scsi::Start_stop::LENGTH),
+		Scsi::Start_stop(addr+15)
+	{ if (verbose_scsi) dump(); }
+
+	void dump()
+	{
+		Genode::log("--- Dump START_STOP command --");
+		Cbw::dump();
+		Scsi::Start_stop::dump();
+	}
+};
+
+
 struct Inquiry : Usb::Cbw, Scsi::Inquiry
 {
 	Inquiry(addr_t addr, uint32_t tag, uint8_t lun)
diff --git a/repos/os/src/drivers/usb_block/main.cc b/repos/os/src/drivers/usb_block/main.cc
index c0966824a1..cbccece766 100644
--- a/repos/os/src/drivers/usb_block/main.cc
+++ b/repos/os/src/drivers/usb_block/main.cc
@@ -169,6 +169,7 @@ struct Usb::Block_driver : Usb::Completion,
 
 		bool no_medium     = false;
 		bool try_again     = false;
+		bool start_stop    = false;
 
 		Usb::Device &device;
 		uint8_t      interface;
@@ -249,22 +250,42 @@ struct Usb::Block_driver : Usb::Completion,
 				uint8_t const asc = r.read<Request_sense_response::Asc>();
 				uint8_t const asq = r.read<Request_sense_response::Asq>();
 
-				enum { MEDIUM_NOT_PRESENT = 0x3a, NOT_READY_TO_READY_CHANGE = 0x28 };
+				bool error = false;
+
+				enum { MEDIUM_NOT_PRESENT         = 0x3a,
+				       NOT_READY_TO_READY_CHANGE  = 0x28,
+				       POWER_ON_OR_RESET_OCCURRED = 0x29,
+				       LOGICAL_UNIT_NOT_READY     = 0x04 };
 				switch (asc) {
+
 				case MEDIUM_NOT_PRESENT:
 					Genode::error("Not ready - medium not present");
 					no_medium = true;
 					break;
-				case NOT_READY_TO_READY_CHANGE: /* asq == 0x00 */
+
+				case NOT_READY_TO_READY_CHANGE:  /* asq == 0x00 */
+				case POWER_ON_OR_RESET_OCCURRED: /* asq == 0x00 */
 					Genode::warning("Not ready - try again");
 					try_again = true;
 					break;
+
+				case LOGICAL_UNIT_NOT_READY:
+
+					if      (asq == 2) start_stop = true; /* initializing command required */
+					else if (asq == 1) try_again  = true; /* initializing in progress */
+					else error = true;
+
+					break;
+
 				default:
+					error = true;
+					break;
+				}
+
+				if (error)
 					Genode::error("Request_sense_response asc: ",
 					              Hex(asc, Hex::PREFIX, Hex::PAD),
 					              " asq: ", Hex(asq, Hex::PREFIX, Hex::PAD));
-					break;
-				}
 				break;
 			}
 			case Csw::LENGTH:
@@ -489,6 +510,14 @@ struct Usb::Block_driver : Usb::Completion,
 							/* do nothing for now */
 						} else if (init.try_again) {
 							init.try_again = false;
+						} else if (init.start_stop) {
+
+							init.start_stop = false;
+							Start_stop start_stop((addr_t)cbw_buffer, SS_TAG, active_lun);
+
+							cbw(cbw_buffer, init, true);
+							csw(init, true);
+
 						} else break;
 					} else break;
 
diff --git a/repos/os/src/drivers/usb_block/scsi.h b/repos/os/src/drivers/usb_block/scsi.h
index 161245ec3b..c4510fc0d3 100644
--- a/repos/os/src/drivers/usb_block/scsi.h
+++ b/repos/os/src/drivers/usb_block/scsi.h
@@ -47,6 +47,7 @@ namespace Scsi {
 	struct Request_sense_response;
 	struct Capacity_response_10;
 	struct Capacity_response_16;
+	struct Start_stop_response;
 
 	struct Cmd_6;
 	struct Test_unit_ready;
@@ -274,7 +275,6 @@ struct Scsi::Inquiry : Cmd_6
 };
 
 
-/* not in use for now but might come in handy in the future */
 struct Scsi::Start_stop : Genode::Mmio
 {
 	enum { LENGTH = 6 };