Hello,
On Thu, Jan 07, 2016 at 04:03:32PM -0800, Florian Fainelli wrote:
> diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
> index d61740e78d6d..b6664c579f9a 100644
> --- a/drivers/ata/libahci.c
> +++ b/drivers/ata/libahci.c
> @@ -595,6 +595,58 @@ int ahci_stop_engine(struct ata_port *ap)
> void __iomem *port_mmio = ahci_port_base(ap);
> u32 tmp;
>
> + /*
> + * On some controllers, stopping a port's DMA engine
> + * while the port is in ALPM state (partial or slumber)
> + * results in failures on subsequent DMA engine starts.
> + * For those controllers, put the port back in active
> + * state before stopping it's DMA engine.
> + */
> + if (ap->flags2 & ATA_FLAG2_WAKE_BEFORE_STOP) {
...
So, I'm not too comfortable with open coding ALPM switching in
ahci_stop_engine(). Shouldn't it be possible to update and/or
refactor and reuse ahci_set_lpm()?
> --- a/include/linux/libata.h
> +++ b/include/linux/libata.h
> @@ -236,6 +236,8 @@ enum {
>
> /* bits 24:31 of ap->flags are reserved for LLD specific flags */
>
> + /* struct ata_port flags2 */
> + ATA_FLAG2_WAKE_BEFORE_STOP = (1 << 0), /* wake link before DMA stop */
What's wrong with bits 2-5 in ATA_FLAG_* space? Also, should this be
a ahci priv flag?
Thanks.
--
tejun
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