qed: Wait for ready indication before rereading the shmem

The MFW might be reset and re-update its shared memory.
Upon the detection of such a reset the driver rereads this memory, but it
has to wait till the data is valid.
This patch adds the missing wait for a data ready indication.

Signed-off-by: Tomer Tayar <Tomer.Tayar@cavium.com>
Signed-off-by: Ariel Elior <Ariel.Elior@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/qlogic/qed/qed_mcp.c b/drivers/net/ethernet/qlogic/qed/qed_mcp.c
index d89a0e22f6e4307896cae0383889c7b5b8f05c22..bdcacb31d88b267d2022b0a66b58bf4b7385c6e7 100644 (file)
--- a/drivers/net/ethernet/qlogic/qed/qed_mcp.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_mcp.c
@@ -183,18 +183,57 @@ int qed_mcp_free(struct qed_hwfn *p_hwfn)
        return 0;
 }
 
+/* Maximum of 1 sec to wait for the SHMEM ready indication */
+#define QED_MCP_SHMEM_RDY_MAX_RETRIES  20
+#define QED_MCP_SHMEM_RDY_ITER_MS      50
+
 static int qed_load_mcp_offsets(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)
 {
        struct qed_mcp_info *p_info = p_hwfn->mcp_info;
+       u8 cnt = QED_MCP_SHMEM_RDY_MAX_RETRIES;
+       u8 msec = QED_MCP_SHMEM_RDY_ITER_MS;
        u32 drv_mb_offsize, mfw_mb_offsize;
        u32 mcp_pf_id = MCP_PF_ID(p_hwfn);
 
        p_info->public_base = qed_rd(p_hwfn, p_ptt, MISC_REG_SHARED_MEM_ADDR);
-       if (!p_info->public_base)
-               return 0;
+       if (!p_info->public_base) {
+               DP_NOTICE(p_hwfn,
+                         "The address of the MCP scratch-pad is not configured\n");
+               return -EINVAL;
+       }
 
        p_info->public_base |= GRCBASE_MCP;
 
+       /* Get the MFW MB address and number of supported messages */
+       mfw_mb_offsize = qed_rd(p_hwfn, p_ptt,
+                               SECTION_OFFSIZE_ADDR(p_info->public_base,
+                                                    PUBLIC_MFW_MB));
+       p_info->mfw_mb_addr = SECTION_ADDR(mfw_mb_offsize, mcp_pf_id);
+       p_info->mfw_mb_length = (u16)qed_rd(p_hwfn, p_ptt,
+                                           p_info->mfw_mb_addr +
+                                           offsetof(struct public_mfw_mb,
+                                                    sup_msgs));
+
+       /* The driver can notify that there was an MCP reset, and might read the
+        * SHMEM values before the MFW has completed initializing them.
+        * To avoid this, the "sup_msgs" field in the MFW mailbox is used as a
+        * data ready indication.
+        */
+       while (!p_info->mfw_mb_length && --cnt) {
+               msleep(msec);
+               p_info->mfw_mb_length =
+                       (u16)qed_rd(p_hwfn, p_ptt,
+                                   p_info->mfw_mb_addr +
+                                   offsetof(struct public_mfw_mb, sup_msgs));
+       }
+
+       if (!cnt) {
+               DP_NOTICE(p_hwfn,
+                         "Failed to get the SHMEM ready notification after %d msec\n",
+                         QED_MCP_SHMEM_RDY_MAX_RETRIES * msec);
+               return -EBUSY;
+       }
+
        /* Calculate the driver and MFW mailbox address */
        drv_mb_offsize = qed_rd(p_hwfn, p_ptt,
                                SECTION_OFFSIZE_ADDR(p_info->public_base,
@@ -204,13 +243,6 @@ static int qed_load_mcp_offsets(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)
                   "drv_mb_offsiz = 0x%x, drv_mb_addr = 0x%x mcp_pf_id = 0x%x\n",
                   drv_mb_offsize, p_info->drv_mb_addr, mcp_pf_id);
 
-       /* Set the MFW MB address */
-       mfw_mb_offsize = qed_rd(p_hwfn, p_ptt,
-                               SECTION_OFFSIZE_ADDR(p_info->public_base,
-                                                    PUBLIC_MFW_MB));
-       p_info->mfw_mb_addr = SECTION_ADDR(mfw_mb_offsize, mcp_pf_id);
-       p_info->mfw_mb_length = (u16)qed_rd(p_hwfn, p_ptt, p_info->mfw_mb_addr);
-
        /* Get the current driver mailbox sequence before sending
         * the first command
         */