diff options
| -rw-r--r-- | Kernel/Devices/HID/I8042Controller.cpp | 56 |
1 files changed, 49 insertions, 7 deletions
diff --git a/Kernel/Devices/HID/I8042Controller.cpp b/Kernel/Devices/HID/I8042Controller.cpp index daf354b071..cb96e364d9 100644 --- a/Kernel/Devices/HID/I8042Controller.cpp +++ b/Kernel/Devices/HID/I8042Controller.cpp @@ -34,19 +34,61 @@ UNMAP_AFTER_INIT I8042Controller::I8042Controller() UNMAP_AFTER_INIT bool I8042Controller::check_existence_via_probing(Badge<HIDManagement>) { { + u8 configuration = 0; SpinlockLocker lock(m_lock); + + // This drains the output buffer and serves as an existence test. + if (auto result = drain_output_buffer(); result.is_error()) { + dbgln("I8042: Trying to flush output buffer as an existence test failed, error {}", result.error()); + return false; + } + // Note: Perform controller self-test before touching the controller // Try to probe the controller for 10 times and give up if nothing // responded. - for (int attempt = 0; attempt < 10; attempt++) { + // Some controllers will reset and behave abnormally on this, so let's ensure + // we keep the configuration before initiating this command. + + if (auto result = do_wait_then_write(I8042Port::Command, I8042Command::ReadConfiguration); result.is_error()) { + dbgln("I8042: Trying to read configuration failed during the existence test, error {}", result.error()); + return false; + } + + { + auto result = do_wait_then_read(I8042Port::Buffer); + if (result.is_error()) { + dbgln("I8042: Trying to read configuration failed during the existence test, error {}", result.error()); + return false; + } + configuration = result.release_value(); + } + + bool successful_self_test = false; + for (int attempt = 0; attempt < 20; attempt++) { do_write(I8042Port::Command, I8042Command::TestPS2Controller); - if (do_read(I8042Port::Buffer) == I8042Response::ControllerTestPassed) - return true; + if (do_read(I8042Port::Buffer) == I8042Response::ControllerTestPassed) { + successful_self_test = true; + break; + } // Note: Wait 500 microseconds in case the controller couldn't respond IO::delay(500); } - dbgln("I8042: Trying to probe for existence of controller failed"); - return false; + if (!successful_self_test) { + dbgln("I8042: Trying to probe for existence of controller failed"); + return false; + } + + if (auto result = do_wait_then_write(I8042Port::Command, I8042Command::WriteConfiguration); result.is_error()) { + dbgln("I8042: Trying to restore configuration after self-test failed with error {}", result.error()); + return false; + } + + if (auto result = do_wait_then_write(I8042Port::Buffer, configuration); result.is_error()) { + dbgln("I8042: Trying to write restored configuration after self-test failed with error {}", result.error()); + return false; + } + + return true; } } @@ -56,7 +98,7 @@ UNMAP_AFTER_INIT ErrorOr<void> I8042Controller::detect_devices() u8 configuration; { SpinlockLocker lock(m_lock); - + // Note: This flushes all the garbage left in the controller registers TRY(drain_output_buffer()); TRY(do_wait_then_write(I8042Port::Command, I8042Command::DisableFirstPS2Port)); @@ -179,7 +221,7 @@ bool I8042Controller::irq_process_input_buffer(HIDDevice::Type instrument_type) ErrorOr<void> I8042Controller::drain_output_buffer() { - for (int attempt = 0; attempt < 5; attempt++) { + for (int attempt = 0; attempt < 50; attempt++) { u8 status = IO::in8(I8042Port::Status); if (!(status & I8042StatusFlag::OutputBuffer)) return {}; |