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usb_block_drv: make device reset optional

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Fixes #2836
This commit is contained in:
Christian Prochaska 2018-05-22 15:32:28 +02:00 committed by Christian Helmuth
parent 0ef7e58ef9
commit 230ed1de37
2 changed files with 28 additions and 11 deletions
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7
repos/os/src/drivers/usb_block/README
View File

@ -14,7 +14,7 @@ driver:
!<start name="usb_block_drv">
! <resource name="RAM" quantum="4M"/>
! <provides> <service name="Block"/> </provides>
! <config label="usb_stick" report="yes" writeable="yes" interface="0" lun="0"/>
! <config label="usb_stick" report="yes" writeable="yes" interface="0" lun="0" reset_device="no" verbose_scsi="no"/>
! <route>
! <service name="Usb"> <child name="usb_drv"/> </service>
! <any-service> <parent/> <any-child/> </any-service>
@ -63,7 +63,10 @@ session client to write to the USB device. Independent thereof the driver will
query the device and will set the Block session operations accordingly. The
'interface' specifies the USB interface the driver should use. If the device
provides multiple SCSI devices the 'lun' attribute is used to select the right
one.
one. When 'reset_device' is enabled, a 'bulk-only mass storage reset' command
is sent to the device at the beginning of the initialization step. This command
caused problems on at least one device, so it is omitted by default. The
'verbose_scsi' attribute can be useful for debugging.
The configuration of the USB block driver cannot be changed at run-time. The
driver is either used in a static system configuration where it is configured

32
repos/os/src/drivers/usb_block/main.cc
View File

@ -153,6 +153,8 @@ struct Usb::Block_driver : Usb::Completion,
uint8_t ep_in = 0;
uint8_t ep_out = 0;
bool reset_device = false;
/*
* Completion used while initializing the device
*/
@ -354,7 +356,8 @@ struct Usb::Block_driver : Usb::Completion,
* Initialize device
*
* All USB transfers in this method are done synchronously. First we reset
* the device, than we query the max LUN. Afterwards we start sending CBWs.
* the device (optional), then we query the max LUN. Afterwards we start
* sending CBWs.
*
* Since it might take some time for the device to get ready to use, we
* have to check the SCSI logical unit several times.
@ -405,21 +408,30 @@ struct Usb::Block_driver : Usb::Completion,
}
try {
/* reset */
Usb::Packet_descriptor p = iface.alloc(0);
iface.control_transfer(p, 0x21, 0xff, 0, active_interface, 100);
if (!p.succeded) {
Genode::error("Could not reset device");
/*
* reset
*
* This command caused write command errors on a
* 'SanDisk Cruzer Force' (0781:557d) USB stick, so it is
* omitted by default.
*/
if (reset_device) {
Usb::Packet_descriptor p = iface.alloc(0);
iface.control_transfer(p, 0x21, 0xff, 0, active_interface, 100);
if (!p.succeded) {
Genode::error("Could not reset device");
iface.release(p);
throw -1;
}
iface.release(p);
throw -1;
}
iface.release(p);
/*
* Let us do GetMaxLUN and simply ignore the return value because none
* of the devices that were tested did infact report another value than 0.
*/
p = iface.alloc(1);
Usb::Packet_descriptor p = iface.alloc(1);
iface.control_transfer(p, 0xa1, 0xfe, 0, active_interface, 100);
uint8_t max_lun = *(uint8_t*)iface.content(p);
if (p.succeded && max_lun == 0) { max_lun = 1; }
@ -728,6 +740,8 @@ struct Usb::Block_driver : Usb::Completion,
active_interface = node.attribute_value<unsigned long>("interface", 0);
active_lun = node.attribute_value<unsigned long>("lun", 0);
reset_device = node.attribute_value<bool>("reset_device", false);
verbose_scsi = node.attribute_value<bool>("verbose_scsi", false);
}