This is a note to let you know that I've just added the patch titled cxl/pci: Make cxl_dvsec_ranges() failure not fatal to cxl_pci to the 5.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cxl-pci-make-cxl_dvsec_ranges-failure-not-fatal-to-c.patch and it can be found in the queue-5.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f788d480b43f0ed17139324d7a0b8c2032272cce Author: Dan Williams <dan.j.williams@xxxxxxxxx> Date: Mon Mar 14 18:22:38 2022 -0700 cxl/pci: Make cxl_dvsec_ranges() failure not fatal to cxl_pci [ Upstream commit 36bfc6ad508af38f212cf5a38147d867fb3f80a8 ] cxl_dvsec_ranges(), the helper for enumerating the presence of an active legacy CXL.mem configuration on a CXL 2.0 Memory Expander, is not fatal for cxl_pci because there is still value to enable mailbox operations even if CXL.mem operation is disabled. Recall that the reason cxl_pci does this initialization and not cxl_mem is to preserve the useful property (for unit testing) that cxl_mem is cxl_memdev + mmio generic, and does not require access to a 'struct pci_dev' to issue config cycles. Update 'struct cxl_endpoint_dvsec_info' to carry either a positive number of non-zero size legacy CXL DVSEC ranges, or the negative error code from __cxl_dvsec_ranges() in its @ranges member. Reported-by: Krzysztof Zach <krzysztof.zach@xxxxxxxxx> Fixes: 560f78559006 ("cxl/pci: Retrieve CXL DVSEC memory info") Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Reviewed-by: Davidlohr Bueso <dave@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/164730735869.3806189.4032428192652531946.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c index c4941a3ca6a8..bb92853c3b93 100644 --- a/drivers/cxl/pci.c +++ b/drivers/cxl/pci.c @@ -462,13 +462,18 @@ static int wait_for_media_ready(struct cxl_dev_state *cxlds) return 0; } -static int cxl_dvsec_ranges(struct cxl_dev_state *cxlds) +/* + * Return positive number of non-zero ranges on success and a negative + * error code on failure. The cxl_mem driver depends on ranges == 0 to + * init HDM operation. + */ +static int __cxl_dvsec_ranges(struct cxl_dev_state *cxlds, + struct cxl_endpoint_dvsec_info *info) { - struct cxl_endpoint_dvsec_info *info = &cxlds->info; struct pci_dev *pdev = to_pci_dev(cxlds->dev); + int hdm_count, rc, i, ranges = 0; struct device *dev = &pdev->dev; int d = cxlds->cxl_dvsec; - int hdm_count, rc, i; u16 cap, ctrl; if (!d) { @@ -545,10 +550,17 @@ static int cxl_dvsec_ranges(struct cxl_dev_state *cxlds) }; if (size) - info->ranges++; + ranges++; } - return 0; + return ranges; +} + +static void cxl_dvsec_ranges(struct cxl_dev_state *cxlds) +{ + struct cxl_endpoint_dvsec_info *info = &cxlds->info; + + info->ranges = __cxl_dvsec_ranges(cxlds, info); } static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) @@ -617,10 +629,7 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) if (rc) return rc; - rc = cxl_dvsec_ranges(cxlds); - if (rc) - dev_warn(&pdev->dev, - "Failed to get DVSEC range information (%d)\n", rc); + cxl_dvsec_ranges(cxlds); cxlmd = devm_cxl_add_memdev(cxlds); if (IS_ERR(cxlmd))