platform/x86:intel/pmc: Improve pmc_core_get_lpm_req()

Minor improvements on pmc_core_get_lpm_req().
1. Move the long comment to be above the function
2. Use %pe to print error pointer
3. Remove unneeded devm_kfree call

These changes improves the code maintainability.

Signed-off-by: Xi Pardee <xi.pardee@linux.intel.com>
Link: https://lore.kernel.org/r/20250425195237.493129-6-xi.pardee@linux.intel.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index 93a335b0ea633c04ceae2899f103de0dc4131d6d..a32adc53da9857bcd17591187bdd91ab28b95e91 100644 (file)
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -1355,6 +1355,50 @@ static u32 pmc_core_find_guid(struct pmc_info *list, const struct pmc_reg_map *m
        return 0;
 }
 
+/*
+ * This function retrieves low power mode requirement data from PMC Low
+ * Power Mode (LPM) table.
+ *
+ * In telemetry space, the LPM table contains a 4 byte header followed
+ * by 8 consecutive mode blocks (one for each LPM mode). Each block
+ * has a 4 byte header followed by a set of registers that describe the
+ * IP state requirements for the given mode. The IP mapping is platform
+ * specific but the same for each block, making for easy analysis.
+ * Platforms only use a subset of the space to track the requirements
+ * for their IPs. Callers provide the requirement registers they use as
+ * a list of indices. Each requirement register is associated with an
+ * IP map that's maintained by the caller.
+ *
+ * Header
+ * +----+----------------------------+----------------------------+
+ * |  0 |      REVISION              |      ENABLED MODES         |
+ * +----+--------------+-------------+-------------+--------------+
+ *
+ * Low Power Mode 0 Block
+ * +----+--------------+-------------+-------------+--------------+
+ * |  1 |     SUB ID   |     SIZE    |   MAJOR     |   MINOR      |
+ * +----+--------------+-------------+-------------+--------------+
+ * |  2 |           LPM0 Requirements 0                           |
+ * +----+---------------------------------------------------------+
+ * |    |                  ...                                    |
+ * +----+---------------------------------------------------------+
+ * | 29 |           LPM0 Requirements 27                          |
+ * +----+---------------------------------------------------------+
+ *
+ * ...
+ *
+ * Low Power Mode 7 Block
+ * +----+--------------+-------------+-------------+--------------+
+ * |    |     SUB ID   |     SIZE    |   MAJOR     |   MINOR      |
+ * +----+--------------+-------------+-------------+--------------+
+ * | 60 |           LPM7 Requirements 0                           |
+ * +----+---------------------------------------------------------+
+ * |    |                  ...                                    |
+ * +----+---------------------------------------------------------+
+ * | 87 |           LPM7 Requirements 27                          |
+ * +----+---------------------------------------------------------+
+ *
+ */
 static int pmc_core_get_lpm_req(struct pmc_dev *pmcdev, struct pmc *pmc, struct pci_dev *pcidev)
 {
        struct telem_endpoint *ep;
@@ -1374,8 +1418,7 @@ static int pmc_core_get_lpm_req(struct pmc_dev *pmcdev, struct pmc *pmc, struct
 
        ep = pmt_telem_find_and_register_endpoint(pcidev, guid, 0);
        if (IS_ERR(ep)) {
-               dev_dbg(&pmcdev->pdev->dev, "couldn't get telem endpoint %ld",
-                       PTR_ERR(ep));
+               dev_dbg(&pmcdev->pdev->dev, "couldn't get telem endpoint %pe", ep);
                return -EPROBE_DEFER;
        }
 
@@ -1387,49 +1430,6 @@ static int pmc_core_get_lpm_req(struct pmc_dev *pmcdev, struct pmc *pmc, struct
                goto unregister_ep;
        }
 
-       /*
-        * PMC Low Power Mode (LPM) table
-        *
-        * In telemetry space, the LPM table contains a 4 byte header followed
-        * by 8 consecutive mode blocks (one for each LPM mode). Each block
-        * has a 4 byte header followed by a set of registers that describe the
-        * IP state requirements for the given mode. The IP mapping is platform
-        * specific but the same for each block, making for easy analysis.
-        * Platforms only use a subset of the space to track the requirements
-        * for their IPs. Callers provide the requirement registers they use as
-        * a list of indices. Each requirement register is associated with an
-        * IP map that's maintained by the caller.
-        *
-        * Header
-        * +----+----------------------------+----------------------------+
-        * |  0 |      REVISION              |      ENABLED MODES         |
-        * +----+--------------+-------------+-------------+--------------+
-        *
-        * Low Power Mode 0 Block
-        * +----+--------------+-------------+-------------+--------------+
-        * |  1 |     SUB ID   |     SIZE    |   MAJOR     |   MINOR      |
-        * +----+--------------+-------------+-------------+--------------+
-        * |  2 |           LPM0 Requirements 0                           |
-        * +----+---------------------------------------------------------+
-        * |    |                  ...                                    |
-        * +----+---------------------------------------------------------+
-        * | 29 |           LPM0 Requirements 27                          |
-        * +----+---------------------------------------------------------+
-        *
-        * ...
-        *
-        * Low Power Mode 7 Block
-        * +----+--------------+-------------+-------------+--------------+
-        * |    |     SUB ID   |     SIZE    |   MAJOR     |   MINOR      |
-        * +----+--------------+-------------+-------------+--------------+
-        * | 60 |           LPM7 Requirements 0                           |
-        * +----+---------------------------------------------------------+
-        * |    |                  ...                                    |
-        * +----+---------------------------------------------------------+
-        * | 87 |           LPM7 Requirements 27                          |
-        * +----+---------------------------------------------------------+
-        *
-        */
        mode_offset = LPM_HEADER_OFFSET + LPM_MODE_OFFSET;
        pmc_for_each_mode(mode, pmcdev) {
                u32 *req_offset = pmc->lpm_req_regs + (mode * num_maps);
@@ -1442,7 +1442,6 @@ static int pmc_core_get_lpm_req(struct pmc_dev *pmcdev, struct pmc *pmc, struct
                        if (ret) {
                                dev_err(&pmcdev->pdev->dev,
                                        "couldn't read Low Power Mode requirements: %d\n", ret);
-                               devm_kfree(&pmcdev->pdev->dev, pmc->lpm_req_regs);
                                goto unregister_ep;
                        }
                        ++req_offset;