ACK/cmnt: [PATCH][SRU Artful] UBUNTU: SAUCE: ahci: thunderx2: stop engine fix update

[Kleber Souza]

On 10/25/17 00:09, dann frazier wrote:
> BugLink: https://bugs.launchpad.net/bugs/1724117
> 
> The current reset fix fails during continuous reboot test. The failure
> happens when both the on-board SATA slots are used and when one of the
> controllers are reset.
> 
> The latest ThunderX2 firmware (3.1) enables hardware error interrupts and
> when the reset fix fails, we get a hang with the print:
> [   14.839308] sd 1:0:0:0: [sdb] 468862128 512-byte logical blocks: (240 GB/224 GiB)
> [   14.846796] sd 1:0:0:0: [sdb] 4096-byte physical blocks
> [   14.852036] sd 1:0:0:0: [sdb] Write Protect is off
> [   14.856843] sd 1:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
> [   14.866022] ata2.00: Enabling discard_zeroes_data
> 
>         *** NBU BAR Error 0x1e25c ***
>          AddrLo 0x1d80180 AddrHi 0x0
> 
> To fix this issue, update the SATA reset fix to increase the delays between register writes.
> 
> Signed-off-by: Jayachandran C <jnair at caviumnetworks.com>
> [ dannf: *** There is no need to carry this forward beyond artful *** ]
> Signed-off-by: dann frazier <dann.frazier at canonical.com>

Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>

Thanks Dann for the additional explanation.

Note: the authorship of the patch needs to be set properly when applying it.

> ---
>  drivers/ata/libahci.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
> index 9116bba1b07d..1d3e614bad2b 100644
> --- a/drivers/ata/libahci.c
> +++ b/drivers/ata/libahci.c
> @@ -679,10 +679,11 @@ int ahci_stop_engine(struct ata_port *ap)
>  			MIDR_CPU_VAR_REV(0, 0),
>  			MIDR_CPU_VAR_REV(0, MIDR_REVISION_MASK))) {
>  		tmp = readl(hpriv->mmio + 0x8000);
> +		udelay(100);
>  		writel(tmp | (1 << 26), hpriv->mmio + 0x8000);
> -		udelay(1);
> +		udelay(100);
>  		writel(tmp & ~(1 << 26), hpriv->mmio + 0x8000);
> -		dev_warn(ap->host->dev, "CN99XX stop engine fix applied!\n");
> +		dev_warn(ap->host->dev, "CN99XX SATA reset workaround applied\n");
>  	}
>  #endif
>  
>