[PATCH v8 3/3] ahci_xgene: Fix the link down in first attempt for the APM X-Gene SoC AHCI SATA host controller driver.
Tejun Heo
tj at kernel.org
Mon Aug 25 12:30:02 PDT 2014
On Sun, Aug 24, 2014 at 12:07:27AM +0530, Suman Tripathi wrote:
> This patch addresses two HW erratas as described below by retrying the
> COMRESET:
>
> 1. During speed negotiation, controller is not able to detect ALIGN
> at GEN3(6Gbps) within 54.6us and results in a timeout. This issue can
> be recovered by issuing a COMRESET.
>
> 2. Although ALIGN detection is successful, 8b/10b and disparity bit
> errors can occur which result in the signature FIS not received
> successfully by the Host controller. Due to this, the PHY communication
> between the host and drive is not established because of CDR(clock and
> data recovery) circuit doesn't lock. This issue can be recoverd by issuing
> a COMRESET.
>
> The above retries are issued only if the port status register PXSTATUS
> reports device presence detected but PHY communication not established.
> The maximum retry attempts are 3.
Didn't I ask you to update the comment to explain what's going on? Or
is the existing comment already sufficient?
Thanks.
--
tejun
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