Mike, After this patch, the return status of UsbBotGetMaxLun seems confusing and useless. Fortunately, there is no one using the return status of it. What do you think?
Thanks, Star -----Original Message----- From: Kinney, Michael D Sent: Thursday, November 16, 2017 11:58 AM To: [email protected] Cc: Zeng, Star <[email protected]>; Dong, Eric <[email protected]> Subject: [Patch V3 2/2] MdeModulePkg/UsbMassStorageDxe: Check Get Max LUN status/value https://bugzilla.tianocore.org/show_bug.cgi?id=767 If a USB Mass Storage device does not support the Get Max LUN command, then the USB I/O Protocol ControlTransfer() service may return an error. If an error is returned for this command, then assume that the device does not support multiple LUNs and return a maximum LUN value of 0. The USB Mass Storage Class Specification states that a maximum LUN value larger than 0x0F is invalid. Add a check to make sure this maximum LUN value is in this valid range, and if it is not, then assume that the device does not support multiple LUNs and return a maximum LUN value of 0. This change improves compatibility with USB FLASH drives that do not support the Get Max LUN command or return an invalid maximum LUN value. Cc: Star Zeng <[email protected]> Cc: Eric Dong <[email protected]> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Michael D Kinney <[email protected]> --- MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassBot.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassBot.c b/MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassBot.c index 4bb7222b89..6afe2ae235 100644 --- a/MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassBot.c +++ b/MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassBot.c @@ -2,7 +2,7 @@ Implementation of the USB mass storage Bulk-Only Transport protocol, according to USB Mass Storage Class Bulk-Only Transport, Revision 1.0. -Copyright (c) 2007 - 2011, Intel Corporation. All rights reserved.<BR> +Copyright (c) 2007 - 2017, Intel Corporation. All rights reserved.<BR> This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at @@ -576,6 +576,18 @@ UsbBotGetMaxLun ( 1, &Result ); + if (EFI_ERROR (Status) || *MaxLun > USB_BOT_MAX_LUN) { + // + // If the Get LUN request returns an error or the MaxLun is larger than + // the maximum LUN value (0x0f) supported by the USB Mass Storage Class + // Bulk-Only Transport Spec, then set MaxLun to 0. + // + // This improves compatibility with USB FLASH drives that have a single LUN + // and either do not return a max LUN value or return an invalid maximum LUN + // value. + // + *MaxLun = 0; + } return Status; } -- 2.14.2.windows.3 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
