Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941621AbcLWKJL (ORCPT ); Fri, 23 Dec 2016 05:09:11 -0500 Received: from smtprelay4.synopsys.com ([198.182.47.9]:52371 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753255AbcLWKJI (ORCPT ); Fri, 23 Dec 2016 05:09:08 -0500 Subject: Re: [PATCH v2] stmmac: CSR clock configuration fix To: Phil Reid , Joao Pinto , , , References: <7b395fd7dfd0c808243a744393473cbbf89b268a.1482410161.git.jpinto@synopsys.com> <15975894-6a5e-1706-ff9e-660c0bac3971@electromag.com.au> <816bb34f-bb4c-648a-179e-7e72cab975b0@electromag.com.au> <67213186-8583-9f9c-6f6a-6f56d2ba4ff0@synopsys.com> CC: , , , , From: Joao Pinto Message-ID: <2dad580c-7c59-f680-0e99-c4af54fb794b@synopsys.com> Date: Fri, 23 Dec 2016 10:09:02 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.107.19.116] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3355 Lines: 95 Hello Phil, ?s 1:09 AM de 12/23/2016, Phil Reid escreveu: > G'day Joao, > On 23/12/2016 01:06, Joao Pinto wrote: >> ?s 4:57 PM de 12/22/2016, Phil Reid escreveu: >>> On 22/12/2016 23:47, Joao Pinto wrote: >>>> >>>> Hello Phil, >>>> >>>> ?s 3:42 PM de 12/22/2016, Phil Reid escreveu: >>>>> G'day Joao, >>>>> >>>>> On 22/12/2016 20:38, Joao Pinto wrote: >>>>>> When testing stmmac with my QoS reference design I checked a problem in the >>>>>> CSR clock configuration that was impossibilitating the phy discovery, since >>>>>> every read operation returned 0x0000ffff. This patch fixes the issue. >>>>>> >>>>>> Signed-off-by: Joao Pinto >>>>>> --- >>>>>> changes v1->v2 (David Miller) >>>>>> - DWMAC100 and DWMAC1000 csr clocks masks should also be fixed for the patch >>>>>> to make sense >>>>>> >>>>>> drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c | 2 +- >>>>>> drivers/net/ethernet/stmicro/stmmac/dwmac100_core.c | 2 +- >>>>>> drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c | 8 ++++---- >>>>>> 3 files changed, 6 insertions(+), 6 deletions(-) >>>>>> >>>>>> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c >>>>>> b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c >>>>>> index b21d03f..94223c8 100644 >>>>>> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c >>>>>> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c >>>>>> @@ -539,7 +539,7 @@ struct mac_device_info *dwmac1000_setup(void __iomem >>>>>> *ioaddr, int mcbins, >>>>>> mac->mii.reg_shift = 6; >>>>>> mac->mii.reg_mask = 0x000007C0; >>>>>> mac->mii.clk_csr_shift = 2; >>>>>> - mac->mii.clk_csr_mask = 0xF; >>>>>> + mac->mii.clk_csr_mask = GENMASK(4, 2); >>>>> >>>>> Should this not be GENMASK(5,2) >>>> >>>> According to Universal MAC databook (valid for MAC100 and MAC1000), we have: >>>> >>>> Bits: 4:2 >>>> 000 60-100 MHz clk_csr_i/42 >>>> 001 100-150 MHz clk_csr_i/62 >>>> 010 20-35 MHz clk_csr_i/16 >>>> 011 35-60 MHz clk_csr_i/26 >>>> 100 150-250 MHz clk_csr_i/102 >>>> 101 250-300 MHz clk_csr_i/124 >>>> 110, 111 Reserved >>>> >>>> So only bits 2, 3 and 4 should be masked. >>>> >>>> Thanks. >>>> >>> But this is a change in behaviour from what was there isn't. >>> Previous mask was 4 bits. now it's 3. >>> >>> And for example the altera socfgpa implementation in the cyclone V has valid >>> values >>> for values 0x8-0xf, using bit 5:2. >> >> According to the databook, bit 5 is reserved and RO. When reserved, it is >> possible to customize. Is that the case? If there is hardware using the 5th bit >> we can put it GENMASK(5, 2) with no problem. >> > I've also checked the Aria 10 documentation and bit 5 is also RW. > The following options are documented and supported > 1000: CSR clock/4 > 1001: CSR clock/6 > 1010: CSR clock/8 > 1011: CSR clock/10 > 1100: CSR clock/12 > 1101: CSR clock/14 > 1110: CSR clock/16 > 1111: CSR clock/18 > They do mention that these values will probably be outside the IEEE 802.3 > specified range. > > But there's at least a couple of cores out there where GENMASK(5,2) is valid. > Can't say if anyone is using that setting thou. Thanks for checking it! Ok, it seems like they are using the reserved bit 5. No problem, I am going to change the patch and put the mask from 2 to 5. Thanks for your help! Joao > >