Re: [PATCH v13 1/5] PCI/TPH: treat reserved 0b10 completer encoding as unsupported

> get_rp_completer_type() returns the Root Port's "TPH Completer
> Supported" field (bits 13:12 of Device Capabilities 2) verbatim. The
> 0b10 encoding is reserved, but pcie_enable_tph() feeds the raw value
> into the requester type:
> 
> 	pdev->tph_req_type = min(pdev->tph_req_type, rp_req_type);
> 
> and later writes tph_req_type to the TPH Requester Enable field, which
> only defines 0b00 (disable), 0b01 (TPH only) and 0b11 (extended TPH).
> 
> No known hardware presents the reserved 0b10 in this field, so this is
> defensive hardening rather than a fix for observed silicon: fold the
> reserved encoding into "not supported" so only the three architected
> values can ever reach the Requester Enable field.
> 
> Signed-off-by: Zhiping Zhang <[email protected]>

Sashiko has reviewed this patch and found no issues. It looks great!

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