On 12/01/2017 23:36, Tony Lindgren wrote:
* Tony Lindgren <tony@xxxxxxxxxxx> [170112 14:31]:
* Jean-Jacques Hiblot <jjhiblot@xxxxxx> [170109 04:23]:
AHCI provides the register PORTS_IMPL to let the software know which port
is supported. The register must be initialized by the bootloader. However
in some cases u-boot doesn't properly initialize this value (if it is not
compiled with SATA support for example or if the SATA initialization fails).
The DTS entry "ports-implemented" can be used to override the value in
PORTS_IMPL.
Adding this entry in the dts allows us no to worry about what is done by
the bootloader.
Adding into omap-for-v4.11/dt thanks.
Actually not applying just yet as I just noticed you tagged this for stable.
Care to describe what breaks and on which devices without this patch?
Hi tony,
Without this patch the SATA will not work in the following two cases:
* if there has been a failure to initialize SATA in u-boot.
* if ahci_platform module has been removed and re-inserted. The reason
is that the content of PORTS_IMPL is lost after the module is removed. I
suspect that it's because the controller is reset by the hwmod.
Jean-Jacques
Regards,
Tony
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