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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?ui/BdnOMjhZC40qZCNFTvf6S/ubqkeFfeS4GxsaLY6c1gL+hb1hijdct2e64?= =?us-ascii?Q?MqWb38NelurCG1VjcC6Z1a/TVGA0QR5KfTDkYhGwLoIlQQTIuuiyIMhORY29?= =?us-ascii?Q?btSeu0lwneA0FHwflX9+dchUWyJRBpOGEp14XznGj9VNmWR5CBmhZzNJLQBF?= =?us-ascii?Q?yHbi0otXrOh4Rt8bH1BRfV6km8xpar77/lhx5G3XZbJrQ1wx63qp7JHng5JE?= =?us-ascii?Q?aOyyNXHCBs/Ol5haj7Ey581It7OeOKaj/kXrIQi03pmOp/vdmlri9Ejsjln9?= =?us-ascii?Q?NOkOqV5IQsJDK5wA8Rynih/6NZIBhR9R4JfF/wMyspCiOr72hyP0A39gb0kj?= =?us-ascii?Q?vDjN2ArC75Qx3QSFOM6wndNrEluRgEMMbiZWKEiHYHiIu52Qbbi8+i335IaT?= =?us-ascii?Q?PxKbXSTbuNz7BxfSJ9KadYcdPpgcfT4fomBbaNMlqFJG8G5Zn+9wu8VjiyM0?= =?us-ascii?Q?AzqrMHnioTshdM9Cw0VbWv5CaaMDWQjZcLsOCs8OfKiRaXD/1crwBBxoBx+B?= =?us-ascii?Q?xBCfq3vuycBaM0fc3cK9lTkbReCyojfVUCKiJcwjaykpgVc4dPZK+N4PTyZX?= =?us-ascii?Q?1qkFiMWzNUjtdnLga7qh9dt2/sqgswkastmNK0v4QPf9LzFPX7pXG+Rhiug8?= =?us-ascii?Q?Tj+9Z5sVS8YCprh7VxainSmaKkM8Nwwk9OIKzqMLFArOikLmbeX8/F/C5zrB?= =?us-ascii?Q?ll344A3beA2OTItl0+4b9B3pJZjkn98IrYnDFVGJuCd/bx+/QbX0w/c469ww?= =?us-ascii?Q?OuijJsCgargu/bIa+J2bxGCdYrDZ+hSWF5bUzJuxNnq9Bms2LsPMWd5OulJy?= =?us-ascii?Q?0uLkwRNF4zKpDbvTk2HPMHLHH4bG+5T2/rKC17gv7Hjm4gG2zvU50cbkUAiP?= =?us-ascii?Q?8AwqoE0I1F0nXITq+PRgERVz44rj+C70ocD9h4rJSx6TW4UR7BgYqC2Atoq7?= =?us-ascii?Q?pe1JHNSVrdAM8MDGfIDbOx9QYYOvTSSB+KQ1nkPgbl3Y4CeYS4BHn+jBi5KQ?= =?us-ascii?Q?6N4fO+Pj9Mn7LegwMB9z3L4Ey/9mrvBQ/hrC0YHo+xSQUZsEV9+LG80bzf/h?= =?us-ascii?Q?pLuWar1dVvX2mQC0Ch2i1MlifNZ7vNaDGPKrmDtN206Uxn/x830O5bs8UKU7?= =?us-ascii?Q?JQCncJMl91l9cWcRl4qh1YE+7t4duMFi16S/RKJ5cUgzImhZK5oaxVh6Q+0H?= =?us-ascii?Q?LbJ5ldXcQLOjPCWryGm9YODyXfTSFmO2qrO+SfYoteixuHIhupBh5BqNdruu?= =?us-ascii?Q?L4WAmetIN+2v/Vq3u+/WM0UFz7XdBK3+tpVIDOiRCSa3RzI4DxDqeZkOs9oI?= =?us-ascii?Q?8D6bIDyQKTBlrSt01nJpUTgtolFfSeYQQTbdCRMF4bl9bCdqKJPDGbku32ak?= =?us-ascii?Q?i1uUznqKjdi5JFfUHx2vKvZjmBdzqlFB09JtA5Lydsz7K4ytwfLhSH8EJQRw?= =?us-ascii?Q?caJG8MbtZOHjZ4KCu5fvunFd8VNwDAwkl5lyY3uF/IZrv5sYqH9E+3SkpV2m?= =?us-ascii?Q?1heJYNyvokzQI9P/iUr0VHaVxkgiz8Y+b6A38icdhtyP7NLbajZJ4OnHwtir?= =?us-ascii?Q?N6EoGY4Tby3kL+c4N6Rp9krgn0QTIgfr03QbDGgw?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: a0174f31-2fc7-4e8c-ce67-08dd781af021 X-MS-Exchange-CrossTenant-AuthSource: CYYPR12MB8750.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Apr 2025 10:32:05.5213 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: KGbnzAgCjJf6zldRcYAled16CpAmPuBi1y7QRIab+/a636EmIWdei+uU5LM09n6+XHcL+2oXKiy0FP0sXWB5Tw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR12MB7384 On 07.04.25 19:27:34, Smita Koralahalli wrote: > According to CXL r3.2 section 8.2.1.2, the PCI_COMMAND register fields, > including Memory Space Enable bit, have no effect on the behavior of an > RCD Upstream Port. Retaining this check may incorrectly cause > cxl_pci_probe() to fail on a valid RCD upstream Port. > > While the specification is explicit only for RCD Upstream Ports, this > check is solely for accessing the RCRB, which is always mapped through > memory space. Therefore, its safe to remove the check entirely. In > practice, firmware reliably enables the Memory Space Enable bit for > RCH Downstream Ports and no failures have been observed. > > Removing the check simplifies the code and avoids unnecessary > special-casing, while relying on BIOS/firmware to configure devices > correctly. Moreover, any failures due to inaccessible RCRB regions > will still be caught either in __rcrb_to_component() or while > parsing the component register block. > > The following failure was observed in dmesg when the check was present: > cxl_pci 0000:7f:00.0: No component registers (-6) > > Fixes: d5b1a27143cb ("cxl/acpi: Extract component registers of restricted hosts from RCRB") > Signed-off-by: Smita Koralahalli Reviewed-by: Robert Richter Thanks Smita. > --- > drivers/cxl/core/regs.c | 4 ---- > 1 file changed, 4 deletions(-)