From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Hunter Subject: Re: [BUG] omap1 fails to boot on clock propagation Date: Tue, 29 Jan 2013 10:58:32 -0600 Message-ID: <5107FFB8.4050008@ti.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from bear.ext.ti.com ([192.94.94.41]:38305 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751392Ab3A2Q6e (ORCPT ); Tue, 29 Jan 2013 11:58:34 -0500 In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: =?UTF-8?B?xYF1a2FzeiBHw7NyYWxjenlr?= Cc: linux-omap@vger.kernel.org On 01/29/2013 03:53 AM, =C5=81ukasz G=C3=B3ralczyk wrote: > Hello, >=20 > Some background: > Recently I've ported Linux to some custom omap1 based (5940 or 1510) > hardware. I've had some initial problems, but after a "dirty" fix I > have a running kernel and I can boot using NFS. Do you mean 5910? I am not familiar with a 5940. > Problem: > On the very beginning kernel boot process stopped on clock propagatio= n > routine (simple freeze, no crash info, nothing). After investigation = I > have found that one memory read is at fault in function > omap1_ckctl_recalc_dsp_domain() in clock.c file: >=20 > dsor =3D 1 << (3 & (__raw_readw(DSP_CKCTL) >> clk->rate_offset)); >=20 > My fix was to exchange read operation with default value of DSP_CKCTL= register: >=20 > dsor =3D 1 << (3 & (0x009000090 >> clk->rate_offset)); >=20 > Since this fix I haven't dug deeper into this problem, but it keeps m= e > thinking how to fix it properly. Any suggestions what might be the > root cause of this? Well looking at the code, in order to access the DSP_CKCTL register you need to enable the api_ck first ... omap1_clk_enable(api_ck_p); dsor =3D 1 << (3 & (__raw_readw(DSP_CKCTL) >> clk->rate_offset)); omap1_clk_disable(api_ck_p); Therefore, I would check if the api_ck is actually being turned on, on your platform. For example ... omap1_clk_enable(api_ck_p); pr_info("ARM_IDLECT2 =3D 0x%x\n", __raw_readw(ARM_IDLECT2)); omap1_clk_disable(api_ck_p); Bit 6 in the ARM_IDLECT2 should be set if the api_ck is enabled. Cheers Jon -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html