The board ID and serial number can reside in separate EEPROM devices. Requiring both reads to succeed before publishing either field makes a missing serial EEPROM block board profile selection and hides an otherwise valid board ID.
Serialize EEPROM discovery, read each field into temporary storage, and publish its readiness only after a successful read. Let devlink report whichever fields are available and make the serial-number sysfs attribute propagate read failures. Signed-off-by: Ahmad Byagowi <[email protected]> --- drivers/ptp/ptp_ocp.c | 129 ++++++++++++++++++++++++++++++------------ 1 file changed, 93 insertions(+), 36 deletions(-) diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c index 3d26ec1f7b9e..31a4c9dfe391 100644 --- a/drivers/ptp/ptp_ocp.c +++ b/drivers/ptp/ptp_ocp.c @@ -21,6 +21,7 @@ #include <net/devlink.h> #include <linux/i2c.h> #include <linux/mtd/mtd.h> +#include <linux/mutex.h> #include <linux/nvmem-consumer.h> #include <linux/crc16.h> #include <linux/dpll.h> @@ -343,6 +344,10 @@ struct ptp_ocp_serial_port { #define OCP_BOARD_ID_LEN 13 #define OCP_SERIAL_LEN 6 +#define OCP_EEPROM_BOARD_ID BIT(0) +#define OCP_EEPROM_SERIAL BIT(1) +#define OCP_EEPROM_ALL (OCP_EEPROM_BOARD_ID | \ + OCP_EEPROM_SERIAL) #define OCP_SMA_NUM 4 #define OCP_SIGNAL_NUM 4 #define OCP_FREQ_NUM 4 @@ -403,7 +408,10 @@ struct ptp_ocp { u16 fw_version; u8 board_id[OCP_BOARD_ID_LEN]; u8 serial[OCP_SERIAL_LEN]; - bool has_eeprom_data; + struct mutex eeprom_lock; /* Serializes EEPROM discovery. */ + bool has_board_id; + bool has_serial; + bool eeprom_error_reported; u32 pps_req_map; int flash_start; u32 utc_tai_offset; @@ -1969,21 +1977,50 @@ ptp_ocp_nvmem_device_put(struct nvmem_device **nvmemp) *nvmemp = NULL; } -static void -ptp_ocp_read_eeprom(struct ptp_ocp *bp) +static int +ptp_ocp_read_eeprom(struct ptp_ocp *bp, unsigned int fields) { const struct ptp_ocp_eeprom_map *map; struct nvmem_device *nvmem; + u8 data[OCP_BOARD_ID_LEN]; + const char *field_name = "data"; const void *tag; - int ret; - - if (!bp->i2c_ctrl) - return; + unsigned int field; + int ret = 0; tag = NULL; nvmem = NULL; + mutex_lock(&bp->eeprom_lock); + fields &= OCP_EEPROM_ALL; + if (bp->has_board_id) + fields &= ~OCP_EEPROM_BOARD_ID; + if (bp->has_serial) + fields &= ~OCP_EEPROM_SERIAL; + if (!fields) + goto out; + if (!bp->i2c_ctrl || !bp->eeprom_map) { + ret = -ENODEV; + goto out; + } for (map = bp->eeprom_map; map->len; map++) { + if (map->bp_offset == offsetof(struct ptp_ocp, board_id)) { + field = OCP_EEPROM_BOARD_ID; + field_name = "board ID"; + if (bp->has_board_id) + continue; + } else if (map->bp_offset == offsetof(struct ptp_ocp, serial)) { + field = OCP_EEPROM_SERIAL; + field_name = "serial number"; + if (bp->has_serial) + continue; + } else { + continue; + } + + if (!(fields & field)) + continue; + if (map->tag != tag) { tag = map->tag; ptp_ocp_nvmem_device_put(&nvmem); @@ -1992,24 +2029,34 @@ ptp_ocp_read_eeprom(struct ptp_ocp *bp) nvmem = ptp_ocp_nvmem_device_get(bp, tag); if (IS_ERR(nvmem)) { ret = PTR_ERR(nvmem); - goto fail; + goto out; } } - ret = nvmem_device_read(nvmem, map->off, map->len, - BP_MAP_ENTRY_ADDR(bp, map)); - if (ret != map->len) - goto fail; + ret = nvmem_device_read(nvmem, map->off, map->len, data); + if (ret < 0) + goto out; + + memcpy(BP_MAP_ENTRY_ADDR(bp, map), data, map->len); + if (field == OCP_EEPROM_BOARD_ID) { + /* Publish the field before marking it ready. */ + smp_store_release(&bp->has_board_id, true); + } else { + /* Publish the field before marking it ready. */ + smp_store_release(&bp->has_serial, true); + } } - bp->has_eeprom_data = true; + ret = 0; out: + if (ret && ret != -EPROBE_DEFER && !bp->eeprom_error_reported) { + dev_err(&bp->pdev->dev, "failed to read EEPROM %s: %pe\n", + field_name, ERR_PTR(ret)); + bp->eeprom_error_reported = true; + } ptp_ocp_nvmem_device_put(&nvmem); - return; - -fail: - dev_err(&bp->pdev->dev, "could not read eeprom: %d\n", ret); - goto out; + mutex_unlock(&bp->eeprom_lock); + return ret; } static struct device * @@ -2156,6 +2203,7 @@ ptp_ocp_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req, struct netlink_ext_ack *extack) { struct ptp_ocp *bp = devlink_priv(devlink); + const char *board_id_key = DEVLINK_INFO_VERSION_GENERIC_BOARD_ID; const char *fw_image; char buf[32]; int err; @@ -2166,24 +2214,24 @@ ptp_ocp_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req, if (err) return err; - if (!bp->has_eeprom_data) { - ptp_ocp_read_eeprom(bp); - if (!bp->has_eeprom_data) - return 0; - } + ptp_ocp_read_eeprom(bp, OCP_EEPROM_ALL); - sprintf(buf, "%pM", bp->serial); - err = devlink_info_serial_number_put(req, buf); - if (err) - return err; + /* Pairs with field publication in ptp_ocp_read_eeprom(). */ + if (smp_load_acquire(&bp->has_serial)) { + sprintf(buf, "%pM", bp->serial); + err = devlink_info_serial_number_put(req, buf); + if (err) + return err; + } - snprintf(buf, sizeof(buf), "%.*s", OCP_BOARD_ID_LEN, - (const char *)bp->board_id); - err = devlink_info_version_fixed_put(req, - DEVLINK_INFO_VERSION_GENERIC_BOARD_ID, - buf); - if (err) - return err; + /* Pairs with field publication in ptp_ocp_read_eeprom(). */ + if (smp_load_acquire(&bp->has_board_id)) { + snprintf(buf, sizeof(buf), "%.*s", OCP_BOARD_ID_LEN, + (const char *)bp->board_id); + err = devlink_info_version_fixed_put(req, board_id_key, buf); + if (err) + return err; + } return 0; } @@ -3757,9 +3805,17 @@ static ssize_t serialnum_show(struct device *dev, struct device_attribute *attr, char *buf) { struct ptp_ocp *bp = dev_get_drvdata(dev); + int ret; - if (!bp->has_eeprom_data) - ptp_ocp_read_eeprom(bp); + /* Pairs with field publication in ptp_ocp_read_eeprom(). */ + if (!smp_load_acquire(&bp->has_serial)) { + ret = ptp_ocp_read_eeprom(bp, OCP_EEPROM_SERIAL); + if (ret) + return ret; + /* Pairs with field publication in ptp_ocp_read_eeprom(). */ + if (!smp_load_acquire(&bp->has_serial)) + return -ENODATA; + } return sysfs_emit(buf, "%pM\n", bp->serial); } @@ -4729,6 +4785,7 @@ ptp_ocp_device_init(struct ptp_ocp *bp, struct pci_dev *pdev) bp->ptp_info = ptp_ocp_clock_info; spin_lock_init(&bp->lock); + mutex_init(&bp->eeprom_lock); for (i = 0; i < __PORT_COUNT; i++) bp->port[i].line = -1; -- 2.50.1 (Apple Git-155)
