Messages in this thread | | | Date | Wed, 4 Oct 2017 21:15:23 -0700 | From | Bjorn Andersson <> | Subject | Re: [PATCH v2 3/5] soc: qcom: smem: Support global partition |
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On Fri 15 Sep 14:02 PDT 2017, Chris Lew wrote:
> > > On 9/15/2017 11:33 AM, Bjorn Andersson wrote: > > On Thu 14 Sep 14:25 PDT 2017, Chris Lew wrote: > > > > [..] > > > +static struct smem_ptable *qcom_smem_get_ptable(struct qcom_smem *smem) > > > { > > > - struct smem_partition_header *header; > > > - struct smem_ptable_entry *entry; > > > struct smem_ptable *ptable; > > > - unsigned remote_host; > > > - u32 version, host0, host1; > > > - int i; > > > + u32 version; > > > ptable = smem->regions[0].virt_base + smem->regions[0].size - SZ_4K; > > > if (memcmp(ptable->magic, SMEM_PTABLE_MAGIC, sizeof(ptable->magic))) > > > - return 0; > > > + return NULL; > > > version = le32_to_cpu(ptable->version); > > > if (version != 1) { > > > dev_err(smem->dev, > > > "Unsupported partition header version %d\n", version); > > > + return ERR_PTR(-EINVAL); > > > > In the calling places NULL and -EINVAL are both treated as -EINVAL, so I > > think it's better to just return NULL here as well as check for !ptable > > in callers. > > > > Regards, > > Bjorn > > > > qcom_smem_enumerate_partitions allowed the partition table to be optional > before. I want to keep that behavior for V11 where smem might only have the > global heap. The probe will continue with a NULL/0 return from > qcom_get_ptable/qcom_smem_enumerate_partitions. >
You're right, I missed that detail.
Which allows me to argue that I do not feel that testing with IS_ERR_OR_NULL() to let a 0 pass through to the caller is not obvious.
I think it's better if you replace the NULL with ERR_PTR(-ENOENT), which you test and forward in both callers and then for the one caller where partitions are optional you check if ret < 0 && ret != -ENOENT.
(Alternatively you check for NULL in enumerate_partitions() and return 0 with a nice comment saying that everything is okay)
Regards, Bjorn
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