From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw0-x242.google.com (mail-yw0-x242.google.com. [2607:f8b0:4002:c05::242]) by gmr-mx.google.com with ESMTPS id m78si675667ywd.4.2016.06.04.08.43.33 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 04 Jun 2016 08:43:33 -0700 (PDT) Received: by mail-yw0-x242.google.com with SMTP id y6so14250105ywe.0 for ; Sat, 04 Jun 2016 08:43:33 -0700 (PDT) Return-Path: Date: Sat, 4 Jun 2016 11:40:36 -0400 From: Jon Mason Subject: Re: [PATCH 2/3] ntb_transport: Check the number of spads the hardware supports Message-ID: <20160604154035.GA11597@kudzu.us> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: To: Logan Gunthorpe Cc: Dave Jiang , Allen Hubbe , John Kading , Sudip Mukherjee , Arnd Bergmann , linux-ntb@googlegroups.com, linux-kernel@vger.kernel.org List-ID: On Fri, Jun 03, 2016 at 02:50:32PM -0600, Logan Gunthorpe wrote: > I'm working on hardware that currently has a limited number of > scratchpad registers and ntb_ndev fails with no clue as to why. I > feel it is better to fail early and provide a reasonable error message > then to fail later on.. > > The same is done to ntb_perf, but it doesn't currently require enough > spads to actually fail. > > Signed-off-by: Logan Gunthorpe > --- > drivers/ntb/ntb_transport.c | 9 +++++++-- > drivers/ntb/test/ntb_perf.c | 8 ++++++-- > 2 files changed, 13 insertions(+), 4 deletions(-) > > diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c > index 2ef9d913..34e7a7a 100644 > --- a/drivers/ntb/ntb_transport.c > +++ b/drivers/ntb/ntb_transport.c > @@ -1037,6 +1037,13 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev) > int node; > int rc, i; > > + mw_count = ntb_mw_count(ndev); > + if (ntb_spad_count(ndev) < (NUM_MWS + 1 + mw_count*2)) { Nit, please add spaces around '*' (per checkpatch) > + dev_err(&ndev->dev, "Not enough scratch pad registers for %s", > + NTB_TRANSPORT_NAME); > + return -EIO; > + } > + > if (ntb_db_is_unsafe(ndev)) > dev_dbg(&ndev->dev, > "doorbell is unsafe, proceed anyway...\n"); > @@ -1052,8 +1059,6 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev) > > nt->ndev = ndev; > > - mw_count = ntb_mw_count(ndev); > - > nt->mw_count = mw_count; > > nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec), > diff --git a/drivers/ntb/test/ntb_perf.c b/drivers/ntb/test/ntb_perf.c > index 30635c8..1815592 100644 > --- a/drivers/ntb/test/ntb_perf.c > +++ b/drivers/ntb/test/ntb_perf.c > @@ -143,8 +143,6 @@ enum { > VERSION = 0, > MW_SZ_HIGH, > MW_SZ_LOW, > - SPAD_MSG, > - SPAD_ACK, Please explicitly point out that this is being modified in the commit message. I don't see them being used, so probably not a big deal (unless Dave Jiang has something queued that will use it). > MAX_SPAD > }; > > @@ -698,6 +696,12 @@ static int perf_probe(struct ntb_client *client, struct ntb_dev *ntb) > > node = dev_to_node(&pdev->dev); > > + if (ntb_spad_count(ntb) < MAX_SPAD) { > + dev_err(&ntb->dev, "Not enough scratch pad registers for %s", > + DRIVER_NAME); > + return -EIO; > + } Move this check above the dev_to_node assignment above. Thanks, Jon > + > perf = kzalloc_node(sizeof(*perf), GFP_KERNEL, node); > if (!perf) { > rc = -ENOMEM; > -- > 2.1.4 >