Commit 35ee1f49 authored by Dan Williams's avatar Dan Williams
Browse files

cxl/mem: Replace redundant debug message with a comment 



cxl_mem_probe() already emits a log message when HDM operation can not
be established. Delete the similar one in cxl_hdm_decode_init().

What is less obvious is why global_ctrl being enabled makes positive
values of info->ranges irrelevant, and the Linux behavior with respect
to the spec recommendation to mirror CXL Range registers with HDM
Decoder Base + Size registers.

Cc: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: default avatarDavidlohr Bueso <dave@stgolabs.net>
Link: https://lore.kernel.org/r/164944616743.454665.7055846627973202403.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 31e624a7

drivers/cxl/mem.c

+10 −4
Original line number Diff line number Diff line
@@ -107,11 +107,17 @@ __mock bool cxl_hdm_decode_init(struct cxl_dev_state *cxlds) 
	global_ctrl = readl(crb + cmap->hdm_decoder.offset +

			    CXL_HDM_DECODER_CTRL_OFFSET);

	global_enable = global_ctrl & CXL_HDM_DECODER_ENABLE;

	if (!global_enable && info->ranges) {

		dev_dbg(cxlds->dev,

			"DVSEC ranges already programmed and HDM decoders not enabled.\n");



	/*

	 * Per CXL 2.0 Section 8.1.3.8.3 and 8.1.3.8.4 DVSEC CXL Range 1 Base

	 * [High,Low] when HDM operation is enabled the range register values

	 * are ignored by the device, but the spec also recommends matching the

	 * DVSEC Range 1,2 to HDM Decoder Range 0,1. So, non-zero info->ranges

	 * are expected even though Linux does not require or maintain that

	 * match.

	 */

	if (!global_enable && info->ranges)

		goto out;

	}



	retval = true;