Author: imp
Date: Fri Oct 26 14:27:37 2018
New Revision: 339775
URL: https://svnweb.freebsd.org/changeset/base/339775

Log:
  Put a workaround in for command timeout malfunctioning
  
  At least one NVMe drive has a bug that makeing the Command Time Out
  PCIe feature unreliable. The workaround is to disable this
  feature. The driver wouldn't deal correctly with a timeout anyway.
  Only do this for drives that are known bad.
  
  Sponsored by: Netflix, Inc
  Differential Revision: https://reviews.freebsd.org/D17708

Modified:
  head/sys/dev/nvme/nvme.c
  head/sys/dev/nvme/nvme_private.h

Modified: head/sys/dev/nvme/nvme.c
==============================================================================
--- head/sys/dev/nvme/nvme.c    Fri Oct 26 12:27:07 2018        (r339774)
+++ head/sys/dev/nvme/nvme.c    Fri Oct 26 14:27:37 2018        (r339775)
@@ -106,6 +106,7 @@ static struct _pcsid
        { 0x05401c5f,           0, 0, "Memblaze Pblaze4", 
QUIRK_DELAY_B4_CHK_RDY },
        { 0xa821144d,           0, 0, "Samsung PM1725", QUIRK_DELAY_B4_CHK_RDY 
},
        { 0xa822144d,           0, 0, "Samsung PM1725a", QUIRK_DELAY_B4_CHK_RDY 
},
+       { 0x01161179,           0, 0, "Toshiba XG5", QUIRK_DISABLE_TIMEOUT },
        { 0x00000000,           0, 0, NULL  }
 };
 
@@ -276,6 +277,25 @@ nvme_attach(device_t dev)
        if (status != 0) {
                nvme_ctrlr_destruct(ctrlr, dev);
                return (status);
+       }
+
+       /*
+        * Some drives do not implement the completion timeout feature
+        * correctly. There's a WAR from the manufacturer to just disable it.
+        * The driver wouldn't respond correctly to a timeout anyway.
+        */
+       if (ep->quirks & QUIRK_DISABLE_TIMEOUT) {
+               int ptr;
+               uint16_t devctl2;
+
+               status = pci_find_cap(dev, PCIY_EXPRESS, &ptr);
+               if (status) {
+                       device_printf(dev, "Can't locate PCIe capability?");
+                       return (status);
+               }
+               devctl2 = pci_read_config(dev, ptr + PCIER_DEVICE_CTL2, 
sizeof(devctl2));
+               devctl2 |= PCIEM_CTL2_COMP_TIMO_DISABLE;
+               pci_write_config(dev, ptr + PCIER_DEVICE_CTL2, devctl2, 
sizeof(devctl2));
        }
 
        /*

Modified: head/sys/dev/nvme/nvme_private.h
==============================================================================
--- head/sys/dev/nvme/nvme_private.h    Fri Oct 26 12:27:07 2018        
(r339774)
+++ head/sys/dev/nvme/nvme_private.h    Fri Oct 26 14:27:37 2018        
(r339775)
@@ -247,7 +247,8 @@ struct nvme_controller {
 
        uint32_t                ready_timeout_in_ms;
        uint32_t                quirks;
-#define QUIRK_DELAY_B4_CHK_RDY 1               /* Can't touch MMIO on disable 
*/
+#define        QUIRK_DELAY_B4_CHK_RDY  1               /* Can't touch MMIO on 
disable */
+#define        QUIRK_DISABLE_TIMEOUT   2               /* Disable broken 
completion timeout feature */
 
        bus_space_tag_t         bus_tag;
        bus_space_handle_t      bus_handle;
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