From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <1521105992.18237.2.camel@suse.com> Subject: Re: [PATCH 2/3] usb: host: pci: introduce PCI vendor ID for Netlogic From: Oliver Neukum To: Richard Leitner , Richard Leitner , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-usb@vger.kernel.org Cc: bhelgaas@google.com, mathias.nyman@intel.com, gregkh@linuxfoundation.org Date: Thu, 15 Mar 2018 10:26:32 +0100 In-Reply-To: <377fb9d5-1cc9-7ab8-c965-2fb0a4dc20f3@skidata.com> References: <20180314102933.21367-1-dev@g0hl1n.net> <20180314102933.21367-3-dev@g0hl1n.net> <1521029854.4511.12.camel@suse.com> <1521041253.4511.16.camel@suse.com> <377fb9d5-1cc9-7ab8-c965-2fb0a4dc20f3@skidata.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: Am Mittwoch, den 14.03.2018, 16:44 +0100 schrieb Richard Leitner: > On 03/14/2018 04:27 PM, Oliver Neukum wrote: > > Am Mittwoch, den 14.03.2018, 14:31 +0100 schrieb Richard Leitner: > > > > > Well, but it does not. Removing a redundant definition is a clear > > benefit. But you are not removing a definition. You are introducing > > a preprocessor constant. Why? > > What is its benefit? > > AFAIK pci_ids.h collects PCI vendor and device IDs in one single > point. As the PCI vendor ID of Netlogic is used in multiple files > IMHO it would be a good idea to add it to pci_ids.h and furthermore > remove it from arch/mips/include/asm/netlogic/xlp-hal/iomap.h (where > it's currently defined). > > Or am I getting things wrong? I think so, yes. We are giving names to constants as a form of comment or to change them at multiple places at once and consistently. So #define XYZ_NETDEV_RESET_RETRIES 2 makes clearly sense. So does #define XYZ_MAGIC_VALUE1 0xab4e because it tells you that you have a magic value. But you will never redefine a PCI vendor ID. In fact you must not. And if you have a comparison like dev->vID == 0x1234 if you change this to dev->vID == SOME_VENDOR_ID what good does this to you? You already knew it was a vendor ID. Now you can name it at a glance. So what? If you have a device you will have to check whether you have some OEM version. You will always go and check the raw number. And if you have a log and need to check whether the check will be true, you will have a number. Using a constant there is nothing but trouble. Yet one more grep. Regards Oliver From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [2/3] usb: host: pci: introduce PCI vendor ID for Netlogic From: Oliver Neukum Message-Id: <1521105992.18237.2.camel@suse.com> Date: Thu, 15 Mar 2018 10:26:32 +0100 To: Richard Leitner , Richard Leitner , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-usb@vger.kernel.org Cc: bhelgaas@google.com, mathias.nyman@intel.com, gregkh@linuxfoundation.org List-ID: QW0gTWl0dHdvY2gsIGRlbiAxNC4wMy4yMDE4LCAxNjo0NCArMDEwMCBzY2hyaWViIFJpY2hhcmQg TGVpdG5lcjoKPiBPbiAwMy8xNC8yMDE4IDA0OjI3IFBNLCBPbGl2ZXIgTmV1a3VtIHdyb3RlOgo+ ID4gQW0gTWl0dHdvY2gsIGRlbiAxNC4wMy4yMDE4LCAxNDozMSArMDEwMCBzY2hyaWViIFJpY2hh cmQgTGVpdG5lcjoKPiA+ID4gCj4gPiBXZWxsLCBidXQgaXQgZG9lcyBub3QuIFJlbW92aW5nIGEg cmVkdW5kYW50IGRlZmluaXRpb24gaXMgYSBjbGVhcgo+ID4gYmVuZWZpdC4gQnV0IHlvdSBhcmUg bm90IHJlbW92aW5nIGEgZGVmaW5pdGlvbi4gWW91IGFyZSBpbnRyb2R1Y2luZwo+ID4gYSBwcmVw cm9jZXNzb3IgY29uc3RhbnQuIFdoeT8KPiA+IFdoYXQgaXMgaXRzIGJlbmVmaXQ/Cj4gCj4gQUZB SUsgcGNpX2lkcy5oIGNvbGxlY3RzIFBDSSB2ZW5kb3IgYW5kIGRldmljZSBJRHMgaW4gb25lIHNp bmdsZSAKPiBwb2ludC4gQXMgdGhlIFBDSSB2ZW5kb3IgSUQgb2YgTmV0bG9naWMgaXMgdXNlZCBp biBtdWx0aXBsZSBmaWxlcwo+IElNSE8gaXQgd291bGQgYmUgYSBnb29kIGlkZWEgdG8gYWRkIGl0 IHRvIHBjaV9pZHMuaCBhbmQgZnVydGhlcm1vcmUKPiByZW1vdmUgaXQgZnJvbSBhcmNoL21pcHMv aW5jbHVkZS9hc20vbmV0bG9naWMveGxwLWhhbC9pb21hcC5oICh3aGVyZQo+IGl0J3MgY3VycmVu dGx5IGRlZmluZWQpLgo+IAo+IE9yIGFtIEkgZ2V0dGluZyB0aGluZ3Mgd3Jvbmc/CgpJIHRoaW5r IHNvLCB5ZXMuIFdlIGFyZSBnaXZpbmcgbmFtZXMgdG8gY29uc3RhbnRzIGFzIGEgZm9ybQpvZiBj b21tZW50IG9yIHRvIGNoYW5nZSB0aGVtIGF0IG11bHRpcGxlIHBsYWNlcyBhdCBvbmNlIGFuZApj b25zaXN0ZW50bHkuCgpTbwoKI2RlZmluZSBYWVpfTkVUREVWX1JFU0VUX1JFVFJJRVMJMgoKbWFr ZXMgY2xlYXJseSBzZW5zZS4gU28gZG9lcwoKI2RlZmluZSBYWVpfTUFHSUNfVkFMVUUxCTB4YWI0 ZQoKYmVjYXVzZSBpdCB0ZWxscyB5b3UgdGhhdCB5b3UgaGF2ZSBhIG1hZ2ljIHZhbHVlLgpCdXQg eW91IHdpbGwgbmV2ZXIgcmVkZWZpbmUgYSBQQ0kgdmVuZG9yIElELiBJbiBmYWN0IHlvdQptdXN0 IG5vdC4gQW5kIGlmIHlvdSBoYXZlIGEgY29tcGFyaXNvbiBsaWtlCgpkZXYtPnZJRCA9PSAweDEy MzQKCmlmIHlvdSBjaGFuZ2UgdGhpcyB0bwoKZGV2LT52SUQgPT0gU09NRV9WRU5ET1JfSUQKCndo YXQgZ29vZCBkb2VzIHRoaXMgdG8geW91PyBZb3UgYWxyZWFkeSBrbmV3IGl0IHdhcyBhIHZlbmRv ciBJRC4KTm93IHlvdSBjYW4gbmFtZSBpdCBhdCBhIGdsYW5jZS4gU28gd2hhdD8gSWYgeW91IGhh dmUgYSBkZXZpY2UKeW91IHdpbGwgaGF2ZSB0byBjaGVjayB3aGV0aGVyIHlvdSBoYXZlIHNvbWUg T0VNIHZlcnNpb24uIFlvdQp3aWxsIGFsd2F5cyBnbyBhbmQgY2hlY2sgdGhlIHJhdyBudW1iZXIu IEFuZCBpZiB5b3UgaGF2ZSBhIGxvZwphbmQgbmVlZCB0byBjaGVjayB3aGV0aGVyIHRoZSBjaGVj ayB3aWxsIGJlIHRydWUsIHlvdSB3aWxsIGhhdmUKYSBudW1iZXIuClVzaW5nIGEgY29uc3RhbnQg dGhlcmUgaXMgbm90aGluZyBidXQgdHJvdWJsZS4gWWV0IG9uZSBtb3JlIGdyZXAuCgoJUmVnYXJk cwoJCU9saXZlcgotLS0KVG8gdW5zdWJzY3JpYmUgZnJvbSB0aGlzIGxpc3Q6IHNlbmQgdGhlIGxp bmUgInVuc3Vic2NyaWJlIGxpbnV4LXVzYiIgaW4KdGhlIGJvZHkgb2YgYSBtZXNzYWdlIHRvIG1h am9yZG9tb0B2Z2VyLmtlcm5lbC5vcmcKTW9yZSBtYWpvcmRvbW8gaW5mbyBhdCAgaHR0cDovL3Zn ZXIua2VybmVsLm9yZy9tYWpvcmRvbW8taW5mby5odG1sCg==