[U-Boot] [PATCH v2] x86: ahci: Make sure interface is not busy after enabling the port

[Simon Glass]

On 31 December 2014 at 02:18, Bin Meng <bmeng.cn at gmail.com> wrote:
>
> Each time U-Boot boots on Intel Crown Bay board, the displayed hard
> drive information is wrong. It could be either wrong capacity or just
> a 'Capacity: not available' message. After enabling the debug switch,
> we can see the scsi inquiry command did not execute successfully.
> However, doing a 'scsi scan' in the U-Boot shell does not expose
> this issue.
>
> SCSI:  Target spinup took 0 ms.
> SATA link 1 timeout.
> AHCI 0001.0100 32 slots 2 ports 3 Gbps 0x3 impl SATA mode
> flags: ncq stag pm led clo only pmp pio slum part ccc apst
> scanning bus for devices...
> ahci_device_data_io: 0 byte transferred.   <--- scsi inquiry fails
> ahci_device_data_io: 512 byte transferred.
> ahci_device_data_io: 512 byte transferred.
> ahci_device_data_io: 512 byte transferred.
>   Device 0: (0:0) Vendor: ATA Prod.:  Rev: ?8
>               Type: Hard Disk
>                           Capacity: 912968.3 MB = 891.5 GB (1869759264 x 512)
>                           Found 1 device(s).
>
> So uninitialized contents on the stack were passed to dev_print() to
> display those wrong information.
>
> The symptom were observed on two hard drives (one is Seagate, the
> other one is Western Digital). The fix is to make sure the AHCI
> interface is not busy by checking the error and status information
> from task file register after enabling the port in ahci_port_start()
> before proceeding other operations like scsi_scan().
>
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>
> ---
>
> Changes in v2:
> - Return error codes in ahci_port_start() when timeout
> - Use get_timer() instead of plain loop when checking tfdata status
>

Reviewed-by: Simon Glass <sjg at chromium.org>

>  drivers/block/ahci.c | 20 +++++++++++++++++++-
>  1 file changed, 19 insertions(+), 1 deletion(-)