ahci: make robuster during resume

During resume the waiting for Cmd::St takes ~2s on a T460p with Intel
AHCI SSD attached. According to the Serial ATA AHCI Spec. wakeup can take
seconds, e.g. chapter 8.2 Power State Mappings of the Serial ATA AHCI spec
(1.3.1).

Issue #5203

repos/os/src/drivers/ahci/ahci.h

@@ -954,6 +954,9 @@ struct Ahci::Port : private Port_base
 	typedef Port_mmio::Ci   Ci;
 
 	typedef Port_mmio::Register_set::Polling_timeout Polling_timeout;
+	typedef Port_mmio::Register_set::Attempts        Attempts;
+	typedef Port_mmio::Register_set::Microseconds    Microseconds;
+
 
 	void ack_irq(Port_mmio &mmio)
 	{
@@ -992,7 +995,11 @@ struct Ahci::Port : private Port_base
 			return;
 
 		try {
-			mmio.wait_for(delayer, Tfd::Sts_bsy::Equal(0));
+			/* wait up to 5s */
+			mmio.wait_for(Port::Attempts(5000),
+			              Port::Microseconds(1000),
+			              delayer,
+			              Tfd::Sts_bsy::Equal(0));
 		} catch (Polling_timeout) {
 			error("HBA busy unable to start command processing.");
 			return;

repos/os/src/drivers/ahci/main.cc

@@ -141,8 +141,6 @@ class Ahci::Driver : Noncopyable
 
 				device_release_if_stopped_and_idle();
 
-				log("driver halted");
-
 				return;
 			}
 
@@ -153,9 +151,13 @@ class Ahci::Driver : Noncopyable
 
 				/* re-start request handling of client sessions */
 				for_each_port([&](auto &port, auto const index, auto) {
-					port.stop_processing = false;
-					port.reinit();
-					_dispatch.session(index);
+					try {
+						port.reinit();
+						port.stop_processing = false;
+						_dispatch.session(index);
+					} catch (...) {
+						error("port ", index, " failed to be resumed");
+					}
 				});
 
 				log("driver resumed");
@@ -221,6 +223,8 @@ class Ahci::Driver : Noncopyable
 			if (pending)
 				return;
 
+			log("driver halted");
+
 			_resources.release_device();
 		}