Messages in this thread | | | Date | Fri, 18 Mar 2022 04:34:20 +0200 | Subject | Re: [PATCH v2] mm/hmm/test: simplify hmm test code: use miscdevice instead of char dev | From | Mika Penttilä <> |
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On 17.3.2022 16.15, Jason Gunthorpe wrote: > On Thu, Mar 17, 2022 at 08:58:52AM +0200, Mika Penttilä wrote: >> @@ -1225,7 +1232,11 @@ static int dmirror_device_init(struct dmirror_device >> *mdevice, int id) >> >> cdev_init(&mdevice->cdevice, &dmirror_fops); >> mdevice->cdevice.owner = THIS_MODULE; >> - ret = cdev_add(&mdevice->cdevice, dev, 1); >> + device_initialize(&mdevice->device); >> + dev_set_name(&mdevice->device, "%s", dmirror_device_names[id]); >> + mdevice->device.devt = dev; >> + >> + ret = cdev_device_add(&mdevice->cdevice, &mdevice->device); >> if (ret) >> return ret; > > Right, miscdev isn't that helpful in the end.. > > Jason >
To wrap up, I could send a v3 formal patch with either this cdev way or the miscdev way.. Both eliminate the user space /proc/devices parsing and mknod'ing. Jason brought up concerns using miscdevice like this, although for this case it works correctly. miscdevice also provides a little more cleanup and simpler code, but the difference is not huge. So what do people prefer?
Thanks, Mika
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