DM814X SATA Limiting Speed to 1.5Gbps instead of 3Gbps

Kinjan Patel

Other Parts Discussed in Thread: PMP

Hi,

I am using the SATA0 Port from DM814X to connect the external Hard disk. Instead of 3Gbps the Target and host is able to communicate only with 1.5Gbps. Sometime Target identifies the link to be 3.0Gbps but during communication the speed is limited to 1.5Gbps. Following are the error messages.

ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata1: hard resetting link
ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata1: hard resetting link
ata1: SATA link down (SStatus 0 SControl 300)
ata1: hard resetting link
ata1: SATA link down (SStatus 0 SControl 300)
ata1: limiting SATA link speed to 1.5 Gbps
ata1: hard resetting link
ata1: SATA link down (SStatus 0 SControl 310)
ata1: limiting SATA link speed to 1.5 Gbps

Layout Details:

1. Max total length of trace from SOC to HDD is 3.7inch (Pairs length matched within 5mil)

2. SATA passes in 2 modules separated by a B2B connector BSH/BTH Series Samtec Connector.

3. Molex/Foxconn SATA Cable is used to interface Hard Disk.

What can be reason for this?

Regards,

Kinjan

over 13 years ago

0 Nick Reed over 13 years ago

Intellectual 465 points

I am unsure if you are using the latest TI PSP and a 6Gbps capable hard disk, but I notice the following in the release notes:

http://processors.wiki.ti.com/index.php/TI81XX_PSP_04.04.00.01_Release_Notes

Known Issues

This section lists known issues observed in this release:

SDOCM00083627

TI81xx: 6Gbps supporting harddisk negotiates at 1.5Gbps on DM8168 Linux PSP package. Both TI816x and TI814x exhibit inter-op issues with Gen3 HDDs

Connect the HDD behind a Gen2 PMP.

0 Kinjan Patel over 13 years ago in reply to Nick Reed

Prodigy 210 points

Thanks for you reply Nick Reed.

I have used the latest PSP 04.04.00.01
I have not used GEN3 HDD. I used GEN2 (3.0Gbps) Seagate Hard disk of PN: ST9500325AS - 2.5inch 500GB
I checked same HDD with DM8168 (Netra) EVM and found working @ 3Gbps all the time. As per my assumption it has to work with DM8148 (Centaurus) also.
Let me know if i am wrong. Also suggest me what else can cause this kind of issue.

Regards
Kinjan

0 Kinjan Patel over 13 years ago in reply to Kinjan Patel

Prodigy 210 points

Hello

We further used the latest ezSDK5.4 and found the improvement as we were able to communicate with 3.0Gbps for low size packets. For upto (4MB approx.) we were able to communicate for 3.0Gbps, but for higher data size, the SATA link is reset sometimes, after recovering the SATA link sometimes it recovers to 3.0 GBPS link again and sometimes it settles down to 1.5 GBPS link.

Note :-

We are using following commands for writing into SATA drive.

dd if=/dev/zero of=/media/sda1/test bs=4096 count=1000

If we increase count value from 1000 to any higher value, SATA link is reset and sometimes it settles down to 3.0 GBPS link again but most of the times it goes to 1.5 GBPS link.

Best Regards

Kinjan

0 Srirama Govindarajan over 13 years ago in reply to Kinjan Patel

TI__Expert 8250 points

can you please attach console logs showing the exact error messages with the "

dd if=/dev/zero of=/media/sda1/test bs=4096 count=1000" option.

0 Kinjan Patel over 13 years ago in reply to Srirama Govindarajan

Prodigy 210 points

Following are the error messages as noted earlier

0 Kinjan Patel over 13 years ago in reply to Kinjan Patel

Prodigy 210 points

I need following inputs if any one can provide us.

SATA Test results are needed on DM8148 EVM. Is that working @ 3Gbps in DM8148 EVM or not.
Confirmation is required from software team whether SATA workaround (About 100MHz external clock) is there in ezSDK release 5.4 or not

Kinjan

0 Pavel Botev over 13 years ago in reply to Kinjan Patel

TI__Guru**** 170625 points

Hi Kinjan,

We are discussing this subject also here: http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/716/p/197523/708355.aspx

Pavel

0 Pavel Botev over 13 years ago in reply to Pavel Botev

TI__Guru**** 170625 points

Hi Kinjan,

I am posting the latest status here also:

The 100Mhz clock source of SATA on DM814x is not rolled into the ezSDK releases – you will need to pick up an additional patch from (against PSP release 04.01.00.07)

link on external repo corresponding to this:

http://arago-project.org/git/projects/?p=linux-omap3.git;a=commit;h=ee3f09c0604b947e5307d810df3a10f8047729e8

Regards,

Pavel

0 Kinjan Patel over 13 years ago in reply to Pavel Botev

Prodigy 210 points

Hi Pavel,

Thanks for your reply.

We will refer the thread from http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/716/p/197523/708355.aspx

The Problem represented in this forum and in above mentioned link are for same project.

Kinjan

Processors

Processors forum

DM814X SATA Limiting Speed to 1.5Gbps instead of 3Gbps

Known Issues