MIME-Version: 1.0
From: Gavin Guo <gavin.guo@canonical.com>
Date: Wed, 27 Sep 2017 15:33:16 +0800
Message-ID: <CA+eFSM1aJRYs__pwtz+8E0TFOeKuKpHoiOkX6Wmm_2HMT1ut5A@mail.gmail.com>
Subject: mptsas driver cannot detect hotplugging disk with the LSI SCSI
 SAS1068 controller in Ubuntu guest on VMware
To: linux-scsi@vger.kernel.org,
        linux-kernel <linux-kernel@vger.kernel.org>
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Sender: linux-kernel-owner@vger.kernel.org
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There is a problem in the latest upstream kernel with the device:

$ grep -i lsi lspci
03:00.0 Serial Attached SCSI controller [0107]: LSI Logic / Symbios
Logic SAS1068 PCI-X Fusion-MPT SAS [1000:0054] (rev 01)

The device is simulated by the VMware ESXi 5.5

When hotplugging a new disk to the Guest Ubuntu OS, the latest kernel
cannot automatically probe the disk. However, on the v3.19.0-80.88
kernel, the disk can be dynamically probed and show the following
info message:

mptsas: ioc0: attaching ssp device: fw_channel 0, fw_id 1, phy 1,
sas_addr 0x5000c29a6bdae0f5
scsi 2:0:1:0: Direct-Access     VMware   Virtual disk     1.0  PQ: 0
ANSI: 2
sd 2:0:1:0: Attached scsi generic sg2 type 0
sd 2:0:1:0: [sdb] 2097152 512-byte logical blocks: (1.07 GB/1.00 GiB)
sd 2:0:1:0: [sdb] Write Protect is off
sd 2:0:1:0: [sdb] Mode Sense: 61 00 00 00
sd 2:0:1:0: [sdb] Cache data unavailable
sd 2:0:1:0: [sdb] Assuming drive cache: write through
 sdb: unknown partition table
sd 2:0:1:0: [sdb] Attached SCSI disk

After looking up the message:
mptsas: ioc0: attaching ssp device: fw_channel 0, fw_id 1, phy 1,
sas_addr 0x5000c29a6bdae0f5

I found it comes from the path:
mptsas_firmware_event_work -> mptsas_send_sas_event ->
mptsas_hotplug_work -> mptsas_add_end_device

I'll appreciate if anyone can give the idea: If it's possible that the
irq from the simulated LSI SAS controller didn't come in to trigger
the event? However, it can work on the v3.19 kernel so if there is
any driver implementation issue in the latest kernel.