If there is no multiplier, the DEV bit of the ATA device register would always be set. It causes that some ATA hard drives don't response the ATA identity command sent to them.
Below is the description about DEV bit in ATA spec: A device is selected when the DEV bit of the Device register is equal to the device number assigned to the device by means of a Device 0/Device 1 jumper or switch, or use of the CSEL signal. Below is the description about DEV bit in SATA spec: When the DEV bit in the Device register is set to one, selecting the non-existent Device 1, the host adapter shall respond to register reads and writes as specified for a Device 0 with no Device 1 present, as defined in the ATA/ATAPI-5 standard. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Cinnamon Shia <[email protected]> --- MdeModulePkg/Bus/Ata/AtaBusDxe/AtaPassThruExecute.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/MdeModulePkg/Bus/Ata/AtaBusDxe/AtaPassThruExecute.c b/MdeModulePkg/Bus/Ata/AtaBusDxe/AtaPassThruExecute.c index a3008f9..a3739fc 100644 --- a/MdeModulePkg/Bus/Ata/AtaBusDxe/AtaPassThruExecute.c +++ b/MdeModulePkg/Bus/Ata/AtaBusDxe/AtaPassThruExecute.c @@ -11,6 +11,7 @@ Cylinder register. Copyright (c) 2009 - 2013, Intel Corporation. All rights reserved.<BR> + (C) Copyright 2016 Hewlett Packard Enterprise Development LP<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 @@ -413,7 +414,7 @@ DiscoverAtaDevice ( // Acb = ZeroMem (&AtaDevice->Acb, sizeof (EFI_ATA_COMMAND_BLOCK)); Acb->AtaCommand = ATA_CMD_IDENTIFY_DRIVE; - Acb->AtaDeviceHead = (UINT8) (BIT7 | BIT6 | BIT5 | (AtaDevice->PortMultiplierPort << 4)); + Acb->AtaDeviceHead = (UINT8) (BIT7 | BIT6 | BIT5 | (AtaDevice->PortMultiplierPort == 0xFFFF ? 0 : (AtaDevice->PortMultiplierPort << 4))); // // Prepare for ATA pass through packet. -- 2.8.1.windows.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
