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x86_64-pc-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230516_102549_596759_B866E73A X-CRM114-Status: GOOD ( 22.07 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org SGkgQ2hyaXMhCgpDaHJpcy5QYWNraGFtQGFsbGllZHRlbGVzaXMuY28ubnogd3JvdGUgb24gVHVl LCAxNiBNYXkgMjAyMyAwNDo0NjozOAorMDAwMDoKCj4gSGkgTWlxdWVsLCBUaG9tYXMsCj4gCj4g QSBoYXJkd2FyZSBjb2xsZWFndWUgcmVwb3J0ZWQgYSBjb25jZXJuIHRvIG1lIGFib3V0IGEgbmV3 IGRlc2lnbiB3ZSBoYXZlIAo+IHVzaW5nIHRoZSBNYXJ2ZWxsIENOOTEzMCBTb0MgKHdoaWNoIEkg dGhpbmsgd2FzIGNhbGxlZCBBcm1hZGEtOEsgYmVmb3JlIAo+IHRoZXkgcmVicmFuZGVkKS4KPiAK PiBCYXNpY2FsbHkgdGhlaXIgY29uY2VybiBpcyB0aGF0IHRoZSB0V0MgdGltaW5nIHRoZXkgb2Jz ZXJ2ZSBpcyBmYXN0ZXIgCj4gKH4xOG5zKSB0aGFuIHRoZSBkb2N1bWVudGVkIG1pbmltdW0gaW4g dGhlIGhhcmR3YXJlIGRhdGFzaGVldCBmb3IgdGhlIAo+IENOOTEzMCAoMjVucykuIEFzaWRlIGZy b20gbm90IG1lZXRpbmcgdGhlIGRhdGFzaGVldCBzcGVjIHdlJ3ZlIG5vdCAKPiBvYnNlcnZlZCBh bnkgb3RoZXIgaXNzdWUgKHlldCkuCgpJIHdvdWxkIGhhdmUgZXhwZWN0ZWQgdGhlIGNvbnRyb2xs ZXIgdG8gc3VwcG9ydCBhbG1vc3QgYW55IGtpbmQgb2YKdGltaW5ncywgaW5jbHVkaW5nIFNEUiBF RE8gbW9kZSA1LiB0V0MgaXMgMjVucyB3aXRoIG1vZGUgNCwgYnV0IDIwIG9uCm1vZGUgNSAoT05G SSkuIFNvIEkgYmVsaWV2ZSB5b3UncmUgcnVubmluZyBhIHN5c3RlbSB3aXRoIGEgY2hpcCB0aGF0 IGlzCm5vdCBjb21wYXRpYmxlIHdpdGggdGhlIGZhc3Rlc3QgbW9kZS4gSWYgdGhhdCBpcyB0aGUg Y2FzZSwgaXQgbWF5CmV4cGxhaW4gd2h5IHlvdSBkb24ndCBzZWUgZXJyb3JzIHdpdGggdGhpcyBj aGlwOiBpdCBtYXkgc3VwcG9ydApzbGlnaHRseSBmYXN0ZXIgdGltaW5ncyB0aGFuIGl0IGFkdmVy dGlzZXMuCgpBbnl3YXksIGlmIHlvdXIgZmluZGluZ3MgYXJlIHRydWUsIGl0IG1lYW5zIHRoZSBj dXJyZW50IGltcGxlbWVudGF0aW9uCmlzIHNsaWdodGx5IG91dCBvZiBzcGVjIGFuZCB0aGUgdGlt aW5nIGNhbGN1bGF0aW9uIG1pZ2h0IHJlcXVpcmUgdG8gYmUKdHdlYWtlZCBhIGxpdHRsZSBiaXQg dG8gcmVkdWNlIHRXQy4KCj4gSSBub3RpY2UgaW4gdGhlIG1hcnZlbGxfbmFuZC5jIGRyaXZlciB0 aGF0IG1hcnZlbGxfbmZjX2luaXQoKSBzZXRzIHRoZSAKPiBOQU5EIENsb2NrIEZyZXF1ZW5jeSBT ZWxlY3QgYml0ICgweEYyNDQwNzAwOjApIHRvIDEgd2hpY2ggcnVucyBhY2NvcmRpbmcgCj4gdG8g dGhlIGRhdGFzaGVldCB0aGUgTkFORCBmbGFzaCBhdCA0MDBNSHogLiBCdXQgdGhlIGNhbGN1bGF0 aW9ucyBpbiAKPiBtYXJ2ZWxsX25mY19zZXR1cF9pbnRlcmZhY2UoKSB1c2UgdGhlIHZhbHVlIGZy b20gCj4gY2xrX2dldF9yYXRlKG5mYy0+Y29yZV9jbGspIHdoaWNoIGlzIHN0aWxsIDI1ME1IeiBz byBJJ20gd29uZGVyaW5nIGlmIAo+IG1heWJlIHRoZSBmYWN0IHRoYXQgdGhlIE5BTkQgZmxhc2gg aXMgYmVpbmcgcnVuIGZhc3RlciBpcyBoYXZpbmcgYW4gCj4gaW1wYWN0IG9uIHRpbWluZ3MgdGhh dCBhcmUgY2FsY3VsYXRlZCBhcm91bmQgdGhlIGNvcmVfY2xrIGZyZXF1ZW5jeS4KCldoYXQgaWYg eW91IHJlc2V0IHRoaXMgYml0PyBEbyB5b3Ugb2JzZXJ2ZSBkaWZmZXJlbnQgdGltaW5ncz8gSSBo b3BlCnlvdSBkbywgb3RoZXJ3aXNlIHRoaXMgaXMgYSBkZWFkLWVuZC4KClRoZSB0aW1pbmdzIGFy ZSBkZXJpdmVkIGZyb20gdGhpcyBjbG9jayBidXQgSSByZW1lbWJlciBzZWVpbmcgZGlmZmVyZW50 CnJhdGVzIHRoYW4gdGhlIG9uZXMgSSBleHBlY3RlZCB3aXRoIG5vIG9idmlvdXMgZXhwbGFuYXRp b24gKHNlZSB0aGUgIioKMiIgaW4gdGhlIGNhbGN1bGF0aW9uIG9mIHBlcmlvZF9ucyBhbmQgdGhl IGNvbW1lbnQgcmlnaHQgYmVsb3cpLiBTbwptYXliZSB0aGlzIGlzIGR1ZSB0byB0aGUgNDAwTUh6 IHZzLiAyNTBNSHogaXNzdWUgeW91IGFyZSByZXBvcnRpbmcsIG9yCnRoZXJlIGlzIGFuIHVuZG9j dW1lbnRlZCBwcmUtc2NhbGVyIGluLWJldHdlZW4gKHRoaXMgaXMgbXkgb3JpZ2luYWwKZ3Vlc3Mp LgoKPiBEbyB5b3UgdGhpbmsgdGhhdCB0aGUgdGltaW5ncyBjYWxjdWxhdGlvbnMgc2hvdWxkIHRh a2UgdGhlIE5BTkQgQ2xvY2sgCj4gRnJlcXVlbmN5IFNlbGVjdCBzZXR0aW5nIGludG8gYWNjb3Vu dD8KClRoZXJlIGlzIG5vdCBtdWNoIGFib3V0IHRoaXMgY2xvY2sgaW4gdGhlIG1hbnVhbCwgc28g aWYgdGhlIGNsb2NrIGlzCmZlZWRpbmcgdGhlIGxvZ2ljIG9mIHRoZSBjb250cm9sbGVyIGdlbmVy YXRpbmcgdGhlIHNpZ25hbHMgb24gdGhlIGJ1cywKdGhlbiB5ZXMuIFlvdSBjYW4gdmVyaWZ5IHRo aXMgd2l0aCB0aGUgdGVzdCBtZW50aW9uZWQgYWJvdmUuCgpDb3VsZCB5b3UgY2hlY2sgdGhlIHZh bHVlcyBzZXQgdG8gdFdQIGFuZCB0V0ggd2l0aCBhbmQgd2l0aG91dCB0aGUgYml0CmFuZCBwcm9i ZSB0aGUgc2lnbmFscyBpbiBib3RoIGNhc2VzPyBNYXliZSB0aGUgIiogMiIgaW4gdGhlCnBlcmlv ZF9ucyBjYWxjdWxhdGlvbiB3aWxsIHZhbmlzaCBpZiB3ZSB1c2UgNDAwTUh6IGFzIGlucHV0IGNs b2NrIHJhdGhlcgp0aGFuIGNsa19nZXRfcmF0ZSgpIChvciBiZXR0ZXIsIGV4cG9zZSB0aGUgYml0 IGFzIGEgbXV4LWNsb2NrIGFuZCB1c2UKaXQgdG8gdGVsbCB0aGUgQ0NGIHRoZSByaWdodCBmcmVx dWVuY3kpIGFuZCB5b3UnbGwgZ2V0IGEgc2hhcnBlciB0V0MgaW4KdGhlIGVuZCwgd2hpY2ggaG9w ZWZ1bGx5IHNob3VsZCBtYXRjaCB0aGUgc3BlYyB0aGlzIHRpbWUuCgpUaGFua3MsCk1pcXXDqGwK Cl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpM aW51eCBNVEQgZGlzY3Vzc2lvbiBtYWlsaW5nIGxpc3QKaHR0cDovL2xpc3RzLmluZnJhZGVhZC5v cmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1tdGQvCg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C47CC77B7F for ; Tue, 16 May 2023 17:25:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231675AbjEPRZs (ORCPT ); Tue, 16 May 2023 13:25:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229571AbjEPRZq (ORCPT ); Tue, 16 May 2023 13:25:46 -0400 Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net [217.70.183.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C7A7E7A for ; Tue, 16 May 2023 10:25:42 -0700 (PDT) Received: (Authenticated sender: miquel.raynal@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id C69CB1C0003; Tue, 16 May 2023 17:25:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1684257941; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aFevxj/rrkp09WHDPC8r1cjBszhyMx/0fchc8f659C8=; b=ah0R2drhxSyAsYICQwRvoJcC+ZAwy8OXWfWdXbNqkI7uilswu7AT4Ot1GJ/Ab2D11Owqhl ttM8vNs01fx7pam7U/I+/+hqueWpKfsCW+VXTUmx24gVOlYSSVpVElVYKLhXD0YttVol8d CkGYLe/Oisveabg+7id3ZwDEqbjsbBWcUs2aGiBsNTqvYZXPuPBvCgwXY/N3GbOqA5YSqX jfVWACoboMNH/sDI2sUXzSP5pH6+d1WMq0BlWk4ml4qWy5dq27+IGY+PCe6AbjCHaZZ4oL qt8JxscjZICxycfQmByooMkkTZkEfs0IXSkOEda9EaycprL0Bormxjc15jLzBw== Date: Tue, 16 May 2023 19:25:38 +0200 From: Miquel Raynal To: Chris Packham Cc: Thomas Petazzoni , "linux-mtd@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: Marvell NFC timings on CN9130 Message-ID: <20230516192538.45b35b6b@xps-13> In-Reply-To: <17a9eee2-d84f-549d-a5ff-da88d43393c1@alliedtelesis.co.nz> References: <17a9eee2-d84f-549d-a5ff-da88d43393c1@alliedtelesis.co.nz> Organization: Bootlin X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Chris! Chris.Packham@alliedtelesis.co.nz wrote on Tue, 16 May 2023 04:46:38 +0000: > Hi Miquel, Thomas, >=20 > A hardware colleague reported a concern to me about a new design we have= =20 > using the Marvell CN9130 SoC (which I think was called Armada-8K before=20 > they rebranded). >=20 > Basically their concern is that the tWC timing they observe is faster=20 > (~18ns) than the documented minimum in the hardware datasheet for the=20 > CN9130 (25ns). Aside from not meeting the datasheet spec we've not=20 > observed any other issue (yet). I would have expected the controller to support almost any kind of timings, including SDR EDO mode 5. tWC is 25ns with mode 4, but 20 on mode 5 (ONFI). So I believe you're running a system with a chip that is not compatible with the fastest mode. If that is the case, it may explain why you don't see errors with this chip: it may support slightly faster timings than it advertises. Anyway, if your findings are true, it means the current implementation is slightly out of spec and the timing calculation might require to be tweaked a little bit to reduce tWC. > I notice in the marvell_nand.c driver that marvell_nfc_init() sets the=20 > NAND Clock Frequency Select bit (0xF2440700:0) to 1 which runs according= =20 > to the datasheet the NAND flash at 400MHz . But the calculations in=20 > marvell_nfc_setup_interface() use the value from=20 > clk_get_rate(nfc->core_clk) which is still 250MHz so I'm wondering if=20 > maybe the fact that the NAND flash is being run faster is having an=20 > impact on timings that are calculated around the core_clk frequency. What if you reset this bit? Do you observe different timings? I hope you do, otherwise this is a dead-end. The timings are derived from this clock but I remember seeing different rates than the ones I expected with no obvious explanation (see the "* 2" in the calculation of period_ns and the comment right below). So maybe this is due to the 400MHz vs. 250MHz issue you are reporting, or there is an undocumented pre-scaler in-between (this is my original guess). > Do you think that the timings calculations should take the NAND Clock=20 > Frequency Select setting into account? There is not much about this clock in the manual, so if the clock is feeding the logic of the controller generating the signals on the bus, then yes. You can verify this with the test mentioned above. Could you check the values set to tWP and tWH with and without the bit and probe the signals in both cases? Maybe the "* 2" in the period_ns calculation will vanish if we use 400MHz as input clock rather than clk_get_rate() (or better, expose the bit as a mux-clock and use it to tell the CCF the right frequency) and you'll get a sharper tWC in the end, which hopefully should match the spec this time. Thanks, Miqu=C3=A8l