From: "Pei, Andy" <andy.pei@intel.com>
To: "Maheshwari, Abhishek" <abhishek.maheshwari@intel.com>,
"maxime.coquelin@redhat.com" <maxime.coquelin@redhat.com>,
"Wang, Xiao W" <xiao.w.wang@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"stable@dpdk.org" <stable@dpdk.org>,
"Xia, Chenbo" <chenbo.xia@intel.com>,
"Mandal, Purna Chandra" <purna.chandra.mandal@intel.com>
Subject: RE: [PATCH v3] vdpa/ifc/base: wait for queue disable before saving q-state
Date: Wed, 2 Nov 2022 14:56:00 +0000 [thread overview]
Message-ID: <MWHPR11MB174115F0626DEF3493063EB28F399@MWHPR11MB1741.namprd11.prod.outlook.com> (raw)
In-Reply-To: <20221102095458.2165448-1-abhishek.maheshwari@intel.com>
> -----Original Message-----
> From: Maheshwari, Abhishek <abhishek.maheshwari@intel.com>
> Sent: Wednesday, November 2, 2022 5:55 PM
> To: maxime.coquelin@redhat.com; Wang, Xiao W <xiao.w.wang@intel.com>
> Cc: dev@dpdk.org; stable@dpdk.org; Xia, Chenbo <Chenbo.Xia@intel.com>;
> Mandal, Purna Chandra <Purna.Chandra.Mandal@intel.com>; Pei, Andy
> <andy.pei@intel.com>; Maheshwari, Abhishek
> <Abhishek.Maheshwari@intel.com>
> Subject: [PATCH v3] vdpa/ifc/base: wait for queue disable before saving q-
> state
>
> Some ifc hardware require synchronization between disabling a queue and
> saving queue-state from LM registers. When queue is disabled from vDPA
> driver, ifc device stops executing new virtio-cmds and then updates LM
> registers with used/avail index. Before saving the queue-state, vDPA driver
> should wait until the queue is disabled from backend.
>
> Fixes: 5d75517beffe ("vdpa/ifc/base: access block device registers")
> Cc: andy.pei@intel.com
> Cc: stable@dpdk.org
>
> Signed-off-by: Abhishek Maheshwari <abhishek.maheshwari@intel.com>
>
> ---
> v2:
> * Fixing the styling issues
> * Addressing comment to avoid reading the register again after
> exhausting the tries
>
> v3:
> * Fixing warning condition
> ---
> drivers/vdpa/ifc/base/ifcvf.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/vdpa/ifc/base/ifcvf.c b/drivers/vdpa/ifc/base/ifcvf.c index
> f1e1474447..06996fd5d7 100644
> --- a/drivers/vdpa/ifc/base/ifcvf.c
> +++ b/drivers/vdpa/ifc/base/ifcvf.c
> @@ -257,6 +257,7 @@ ifcvf_hw_disable(struct ifcvf_hw *hw)
> u32 i;
> struct ifcvf_pci_common_cfg *cfg;
> u32 ring_state;
> + int q_disable_try;
>
> cfg = hw->common_cfg;
> if (!cfg) {
> @@ -275,6 +276,21 @@ ifcvf_hw_disable(struct ifcvf_hw *hw)
> continue;
> }
>
> + /* Some ifc hardware require synchronization between
> disabling a
> + * queue and saving queue-state from LM registers. When
> queue is
> + * disabled from vDPA driver, ifc device stops executing new
> + * virtio-cmds and then updates LM registers with used/avail
> + * index. Before saving the queue-state, vDPA driver waits
> until
> + * the queue is disabled from backend.
> + */
> + q_disable_try = 10;
> + while (q_disable_try-- && IFCVF_READ_REG16(&cfg-
> >queue_enable))
> + msec_delay(10);
> +
> + if (!q_disable_try)
> + WARNINGOUT("Failed Q:%d disable, Saved state
> invalid\n",
> + i);
> +
> if (hw->device_type == IFCVF_BLK)
> ring_state = *(u32 *)(hw->lm_cfg +
> IFCVF_LM_RING_STATE_OFFSET +
> --
> 2.31.1
Acked-by: Andy Pei <andy.pei@intel.com>
next prev parent reply other threads:[~2022-11-02 14:56 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20221025072302.1683505-1-abhishek.maheshwari@intel.com>
2022-11-02 3:22 ` [PATCH v2] " Abhishek Maheshwari
2022-11-02 9:54 ` [PATCH v3] " Abhishek Maheshwari
2022-11-02 14:56 ` Pei, Andy [this message]
2022-11-03 2:37 ` Xia, Chenbo
2022-11-03 4:36 ` [PATCH v4] " Abhishek Maheshwari
2022-11-03 9:35 ` [PATCH v5] " Abhishek Maheshwari
2022-11-04 2:31 ` Xia, Chenbo
2022-11-04 2:38 ` Mandal, Purna Chandra
2022-11-10 7:02 ` Xia, Chenbo
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