Messages in this thread | | | Subject | Re: [PATCH v2] Bugfix for handling of shadow doorbell buffer. | From | Sagi Grimberg <> | Date | Thu, 16 Aug 2018 14:20:08 -0700 |
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> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c > index 17a0190bd88f..4452f8553301 100644 > --- a/drivers/nvme/host/pci.c > +++ b/drivers/nvme/host/pci.c > @@ -306,6 +306,14 @@ static bool nvme_dbbuf_update_and_check_event(u16 value, u32 *dbbuf_db, > old_value = *dbbuf_db; > *dbbuf_db = value; > > + /* > + * Ensure that the doorbell is updated before reading > + * the EventIdx from memory. NVMe controller should have > + * similar ordering guarantees - update EventIdx before > + * reading doorbell. > + */ > + mb(); > + > if (!nvme_dbbuf_need_event(*dbbuf_ei, value, old_value)) > return false; > }
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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