cxgb4: Properly revert VPD changes

Clang warns:

drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:2785:2: error: variable 'kw_offset' is uninitialized when used here [-Werror,-Wuninitialized]
        FIND_VPD_KW(i, "RV");
        ^~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:2776:39: note: expanded from macro 'FIND_VPD_KW'
        var = pci_vpd_find_info_keyword(vpd, kw_offset, vpdr_len, name); \
                                             ^~~~~~~~~
drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:2748:34: note: initialize the variable 'kw_offset' to silence this warning
        unsigned int vpdr_len, kw_offset, id_len;
                                        ^
                                         = 0
drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:2785:2: error: variable 'vpdr_len' is uninitialized when used here [-Werror,-Wuninitialized]
        FIND_VPD_KW(i, "RV");
        ^~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:2776:50: note: expanded from macro 'FIND_VPD_KW'
        var = pci_vpd_find_info_keyword(vpd, kw_offset, vpdr_len, name); \
                                                        ^~~~~~~~
drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:2748:23: note: initialize the variable 'vpdr_len' to silence this warning
        unsigned int vpdr_len, kw_offset, id_len;
                             ^
                              = 0
2 errors generated.

The series "PCI/VPD: Convert more users to the new VPD API functions"
was applied to net-next when it should have been applied to the PCI tree
because of build errors. However, commit 82e34c8a ("Revert "Revert
"cxgb4: Search VPD with pci_vpd_find_ro_info_keyword()""") reapplied a
change, resulting in the warning above.

Properly revert commit 8d63ee60 ("cxgb4: Search VPD with
pci_vpd_find_ro_info_keyword()") to fix the warning and restore proper
functionality. This also reverts commit 3a93bede ("cxgb4: Remove
unused vpd_param member ec") to avoid future merge conflicts, as that
change has been applied to the PCI tree.

Link: https://lore.kernel.org/r/20210823120929.7c6f7a4f@canb.auug.org.au/
Link: https://lore.kernel.org/r/1ca29408-7bc7-4da5-59c7-87893c9e0442@gmail.com/Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cxgb4.h

@@ -84,6 +84,7 @@ extern struct mutex uld_mutex;
 enum {
 	MAX_NPORTS	= 4,     /* max # of ports */
 	SERNUM_LEN	= 24,    /* Serial # length */
+	EC_LEN		= 16,    /* E/C length */
 	ID_LEN		= 16,    /* ID length */
 	PN_LEN		= 16,    /* Part Number length */
 	MACADDR_LEN	= 12,    /* MAC Address length */
@@ -390,6 +391,7 @@ struct tp_params {
 
 struct vpd_params {
 	unsigned int cclk;
+	u8 ec[EC_LEN + 1];
 	u8 sn[SERNUM_LEN + 1];
 	u8 id[ID_LEN + 1];
 	u8 pn[PN_LEN + 1];

drivers/net/ethernet/chelsio/cxgb4/t4_hw.c

@@ -2744,6 +2744,7 @@ int t4_seeprom_wp(struct adapter *adapter, bool enable)
 int t4_get_raw_vpd_params(struct adapter *adapter, struct vpd_params *p)
 {
 	int i, ret = 0, addr;
+	int ec, sn, pn, na;
 	u8 *vpd, csum, base_val = 0;
 	unsigned int vpdr_len, kw_offset, id_len;
 
@@ -2771,6 +2772,23 @@ int t4_get_raw_vpd_params(struct adapter *adapter, struct vpd_params *p)
 	}
 
 	id_len = pci_vpd_lrdt_size(vpd);
+	if (id_len > ID_LEN)
+		id_len = ID_LEN;
+
+	i = pci_vpd_find_tag(vpd, VPD_LEN, PCI_VPD_LRDT_RO_DATA);
+	if (i < 0) {
+		dev_err(adapter->pdev_dev, "missing VPD-R section\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	vpdr_len = pci_vpd_lrdt_size(&vpd[i]);
+	kw_offset = i + PCI_VPD_LRDT_TAG_SIZE;
+	if (vpdr_len + kw_offset > VPD_LEN) {
+		dev_err(adapter->pdev_dev, "bad VPD-R length %u\n", vpdr_len);
+		ret = -EINVAL;
+		goto out;
+	}
 
 #define FIND_VPD_KW(var, name) do { \
 	var = pci_vpd_find_info_keyword(vpd, kw_offset, vpdr_len, name); \
@@ -2793,14 +2811,28 @@ int t4_get_raw_vpd_params(struct adapter *adapter, struct vpd_params *p)
 		goto out;
 	}
 
+	FIND_VPD_KW(ec, "EC");
+	FIND_VPD_KW(sn, "SN");
+	FIND_VPD_KW(pn, "PN");
+	FIND_VPD_KW(na, "NA");
+#undef FIND_VPD_KW
+
+	memcpy(p->id, vpd + PCI_VPD_LRDT_TAG_SIZE, id_len);
+	strim(p->id);
+	memcpy(p->ec, vpd + ec, EC_LEN);
+	strim(p->ec);
+	i = pci_vpd_info_field_size(vpd + sn - PCI_VPD_INFO_FLD_HDR_SIZE);
+	memcpy(p->sn, vpd + sn, min(i, SERNUM_LEN));
+	strim(p->sn);
+	i = pci_vpd_info_field_size(vpd + pn - PCI_VPD_INFO_FLD_HDR_SIZE);
+	memcpy(p->pn, vpd + pn, min(i, PN_LEN));
+	strim(p->pn);
+	memcpy(p->na, vpd + na, min(i, MACADDR_LEN));
+	strim((char *)p->na);
+
 out:
 	vfree(vpd);
-	if (ret < 0) {
-		dev_err(adapter->pdev_dev, "error reading VPD\n");
-		return ret;
-	}
-
-	return 0;
+	return ret < 0 ? ret : 0;
 }
 
 /**