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Re: [Qemu-devel] [PATCH 01/17] ahci: Fix CD-ROM signature
From: |
Hannes Reinecke |
Subject: |
Re: [Qemu-devel] [PATCH 01/17] ahci: Fix CD-ROM signature |
Date: |
Wed, 29 Oct 2014 09:11:22 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.0 |
On 10/29/2014 09:07 AM, Markus Armbruster wrote:
> Copying John Snow for additional AHCI expertise.
>
> Hannes Reinecke <address@hidden> writes:
>
>> The CD-ROM signature is 0xeb140101, not 0xeb140000.
>> Without this change OVMF/Duet runs into a timeout trying
>> to detect a SATA cdrom.
>>
>> Signed-off-by: Hannes Reinecke <address@hidden>
>> ---
>> hw/ide/ahci.h | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/hw/ide/ahci.h b/hw/ide/ahci.h
>> index e223258..970eea8 100644
>> --- a/hw/ide/ahci.h
>> +++ b/hw/ide/ahci.h
>> @@ -161,7 +161,7 @@
>> #define AHCI_CMD_HDR_CMD_FIS_LEN 0x1f
>> #define AHCI_CMD_HDR_PRDT_LEN 16
>>
>> -#define SATA_SIGNATURE_CDROM 0xeb140000
>> +#define SATA_SIGNATURE_CDROM 0xeb140101
>> #define SATA_SIGNATURE_DISK 0x00000101
>>
>> #define AHCI_GENERIC_HOST_CONTROL_REGS_MAX_ADDR 0x20
This is actually required by DUET/OVMF.
It just does this check:
(sig & 0xFFFF) == 0x0101
and hence will run into a timeout when a CDROM is attached
to ahci.
It's even in the ATA spec ...
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
address@hidden +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
[Qemu-devel] [PATCH 05/17] scsi: Remove 'lun' argument, Hannes Reinecke, 2014/10/29