From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-sn1nam01on0129.outbound.protection.outlook.com ([104.47.32.129] helo=NAM01-SN1-obe.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.89 #1 (Red Hat Linux)) id 1eTv8A-0003G1-5l for linux-mtd@lists.infradead.org; Tue, 26 Dec 2017 19:43:20 +0000 From: Trent Piepho To: "linux-mtd@lists.infradead.org" , "linux@armlinux.org.uk" , "broonie@kernel.org" , "cyrille.pitchen@wedev4u.fr" , "dwmw2@infradead.org" , "computersforpeace@gmail.com" , "boris.brezillon@free-electrons.com" , "vigneshr@ti.com" , "richard@nod.at" , "marek.vasut@gmail.com" CC: "linux-spi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "nicolas.ferre@microchip.com" , "robh@kernel.org" , "radu.pirea@microchip.com" , "devicetree@vger.kernel.org" Subject: Re: [PATCH 1/3] mtd: spi-nor: add optional DMA-safe bounce buffer for data transfer Date: Tue, 26 Dec 2017 19:43:05 +0000 Message-ID: <1514317385.26695.39.camel@impinj.com> References: In-Reply-To: Content-Language: en-US Content-Type: text/plain; charset="utf-8" Content-ID: Content-Transfer-Encoding: base64 MIME-Version: 1.0 List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , T24gU3VuLCAyMDE3LTEyLTI0IGF0IDA1OjM2ICswMTAwLCBDeXJpbGxlIFBpdGNoZW4gd3JvdGU6 DQo+IA0KPiBUaGVuIHRoZSBwYXRjaCBhZGRzIHR3byBoYXJkd2FyZSBjYXBhYmlsaXRpZXMgZm9y IFNQSSBmbGFzaCBjb250cm9sbGVycywNCj4gU05PUl9IV0NBUFNfV1JfQk9VTkNFIGFuZCBTTk9S X0hXQ0FQU19SRF9CT1VOQ0UuDQoNCkFyZSB0aGVyZSBhbnkgZHJpdmVycyBmb3Igd2hpY2ggYSBi b3VuY2UgYnVmZmVyIGlzIE5PVCBuZWVkZWQgd2hlbiB0aGUNCnR4L3J4IGJ1ZmZlciBpcyBub3Qg aW4gRE1BIHNhZmUgbWVtb3J5PyAgTWF5YmUgaXQgd291bGQgbWFrZSBtb3JlIHNlbnNlDQp0byBp bnZlcnQgdGhlIHNlbnNlIG9mIHRoZXNlIGZsYWdzLCBzbyB0aGF0IHRoZXkgaW5kaWNhdGUgdGhl IGRyaXZlcg0KZG9lcyBub3QgbmVlZCBETUEgc2FmZSBidWZmZXJzLCBpZiB0aGF0IGlzIHRoZSB1 bmNvbW1vbi9ub24tZXhpc3RlbnQNCmNhc2UsIHNvIHRoYXQgZmV3ZXIgZHJpdmVycyBuZWVkIHRv IGJlIG1vZGlmaWVkIHRvIHRvIGJlIGZpeGVkPw0KDQo+ICtzdGF0aWMgYm9vbCBzcGlfbm9yX2lz X2RtYV9zYWZlKGNvbnN0IHZvaWQgKmJ1ZikNCj4gK3sNCj4gKwlpZiAoaXNfdm1hbGxvY19hZGRy KGJ1ZikpDQo+ICsJCXJldHVybiBmYWxzZTsNCj4gKw0KPiArI2lmZGVmIENPTkZJR19ISUdITUVN DQo+ICsJaWYgKCh1bnNpZ25lZCBsb25nKWJ1ZiA+PSBQS01BUF9CQVNFICYmDQo+ICsJICAgICh1 bnNpZ25lZCBsb25nKWJ1ZiA8IChQS01BUF9CQVNFICsgKExBU1RfUEtNQVAgKiBQQUdFX1NJWkUp KSkNCj4gKwkJcmV0dXJuIGZhbHNlOw0KPiArI2VuZGlmDQoNCkl0IGxvb2tzIGxpa2U6DQoNCih1 bnNpZ25lZCBsb25nKWFkZHIgPj0gUEtNQVBfQUREUigwKSAmJg0KKHVuc2lnbmVkIGxvbmcpYWRk ciA8IFBLTUFQX0FERFIoTEFTVF9QS01BUCkNCg0KaXMgdGhlIGV4cHJlc3Npb24gdXNlZCBpbiB0 aGUgaGlnaG1lbSBjb2RlLiAgQnV0IHJlYWxseSwgaXNuJ3QgdGhpcw0KYmVnZ2luZyBmb3IgaXNf aGlnaG1lbV9hZGRyKCkgaW4gaW5jbHVkZS9saW51eC9tbS5oIHRoYXQgY2FuIGFsd2F5cw0KcmV0 dXJuIGZhbHNlIHdoZW4gaGlnaG1lbSBpcyBub3QgZW5hYmxlZD8NCg0KSW4gb3JkZXIgdG8gYmUg c2FmZSwgdGhpcyBtdXN0IGJlIGNhbGxlZCB3aGVuIG5vci0+bG9jayBpcyBoZWxkLCByaWdodD8N CiBPdGhlcndpc2UgaXQgY291bGQgcmFjZSBhZ2FpbnN0IHR3byBjYWxsZXJzIGFsbG9jYXRpbmcg dGhlIGJ1ZmZlciBhdA0KdGhlIHNhbWUgdGltZS4gIFRoYXQgc2hvdWxkIHByb2JhYmx5IGJlIG5v dGVkIGluIHRoZSBrZXJuZWxkb2MgY29tbWVudHMNCmZvciB0aGlzIGZ1bmN0aW9uLCB3aGljaCBz aG91bGQgYWxzbyBiZSB3cml0dGVuLg0KDQo+ICtzdGF0aWMgaW50IHNwaV9ub3JfZ2V0X2JvdW5j ZV9idWZmZXIoc3RydWN0IHNwaV9ub3IgKm5vciwNCj4gKwkJCQkgICAgIHVfY2hhciAqKmJ1ZmZl ciwNCj4gKwkJCQkgICAgIHNpemVfdCAqYnVmZmVyX3NpemUpDQo+ICt7DQoNCj4gKw0KPiArCSpi dWZmZXIgPSBub3ItPmJvdW5jZV9idWZmZXI7DQo+ICsJKmJ1ZmZlcl9zaXplID0gc2l6ZTsNCg0K U28gdGhlIGJ1ZmZlciBpcyByZXR1cm5lZCB2aWEgdGhlIHBhcmFtZXRlciwgYW5kIGFsc28gdmlh IGEgZmllbGQNCmluc2lkZSBub3IuICBTZWVtcyByZWR1bmRhbnQuICBDb25zaWRlciBhZGRyZXNz IGNvdWxkIGJlIHJldHVybmVkIHZpYQ0KdGhlIGZ1bmN0aW9uIHJldHVybiB2YWx1ZSBjb3VwbGVk IHdpdGggUFRSX0VSUigpIGZvciB0aGUgZXJyb3IgY2FzZXMuIA0KT3Igbm90IHJldHVybiBhZGRy ZXNzIGF0IGFsbCBzaW5jZSBpdCdzIGF2YWlsYWJsZSB2aWEgbm9yLQ0KPmJvdW5jZV9idWZmZXIu DQoNCj4gIHsNCj4gIAlzdHJ1Y3Qgc3BpX25vciAqbm9yID0gbXRkX3RvX3NwaV9ub3IobXRkKTsN Cj4gKwlib29sIHVzZV9ib3VuY2UgPSAobm9yLT5mbGFncyAmIFNOT1JfRl9VU0VfUkRfQk9VTkNF KSAmJg0KPiArCQkJICAhc3BpX25vcl9pc19kbWFfc2FmZShidWYpOw0KPiArCXVfY2hhciAqYnVm ZmVyID0gYnVmOw0KPiArCXNpemVfdCBidWZmZXJfc2l6ZSA9IDA7DQo+ICAJaW50IHJldDsNCj4g IA0KPiAgCWRldl9kYmcobm9yLT5kZXYsICJmcm9tIDB4JTA4eCwgbGVuICV6ZFxuIiwgKHUzMilm cm9tLCBsZW4pOw0KPiBAQCAtMTI2OCwxMyArMTMyNCwyMyBAQCBzdGF0aWMgaW50IHNwaV9ub3Jf cmVhZChzdHJ1Y3QgbXRkX2luZm8gKm10ZCwgbG9mZl90IGZyb20sIHNpemVfdCBsZW4sDQo+ICAJ aWYgKHJldCkNCj4gIAkJcmV0dXJuIHJldDsNCj4gIA0KPiArCWlmICh1c2VfYm91bmNlKSB7DQo+ ICsJCXJldCA9IHNwaV9ub3JfZ2V0X2JvdW5jZV9idWZmZXIobm9yLCAmYnVmZmVyLCAmYnVmZmVy X3NpemUpOw0KPiArCQlpZiAocmV0IDwgMCkNCj4gKwkJCWdvdG8gcmVhZF9lcnI7DQo+ICsJfQ0K DQpUaGlzIHBhdHRlcm4sIGNoZWNrIGlmIGJvdW5jZSBpcyBlbmFibGVkLCBjaGVjayBpZiBhZGRy ZXNzIGlzIGRtYS0NCnVuc2FmZSwgZ2V0IGJvdW5jZSBidWZmZXIsIHNlZW1zIHRvIGJlIHZlcnkg Y29tbW9uLiAgQ291bGQgaXQgYmUNCnJlZmFjdG9yZWQgaW50byBvbmUgaGVscGVyPw0KDQp1X2No YXIgKmJ1ZmZlciA9IHNwaV9ub3JfY2hlY2tfYm91bmNlKG5vciwgYnVmLCBsZW4sICZidWZmZXJf c2l6ZSk7DQppZiAoSVNfRVJSKGJ1ZmZlcikpIA0KICAgIHJldHVybiBQVFJfRVJSKGJ1ZmZlcik7 DQovLyBidWZmZXIgPSBub3ItPmJvdW5jZV9idWZmZXIgb3IgYnVmLCB3aGljaGV2ZXIgaXMgY29y cmVjdA0KLy8gYnVmZmVyX3NpemUgPSBsZW4gb3IgYm91bmNlIGJ1ZmZlciBzaXplLCB3aGljaGV2 ZXIgaXMgY29ycmVjdA0KDQpDb3VsZCBzcGlfbm9yX3JlYWRfc2ZkcF9kbWFfdW5zYWZlKCkgYWxz byB1c2UgdGhpcyBidWZmZXI/DQo=