From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dVEen-0008K4-O2 for barebox@lists.infradead.org; Wed, 12 Jul 2017 10:14:11 +0000 Message-ID: <1499854427.6374.19.camel@pengutronix.de> From: Philipp Zabel Date: Wed, 12 Jul 2017 12:13:47 +0200 In-Reply-To: <1499853163.6374.10.camel@pengutronix.de> References: <20170711093050.23278-1-p.zabel@pengutronix.de> <1499849768.5060.32.camel@pengutronix.de> <1499853163.6374.10.camel@pengutronix.de> Mime-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH] i.MX: clk-pllv3: Initially disable PLL_BYPASS bit To: Lucas Stach Cc: Andrey Smirnov , "barebox@lists.infradead.org" On Wed, 2017-07-12 at 11:52 +0200, Philipp Zabel wrote: > On Wed, 2017-07-12 at 10:56 +0200, Lucas Stach wrote: > > Am Dienstag, den 11.07.2017, 12:41 -0500 schrieb Andrey Smirnov: > > > On Tue, Jul 11, 2017 at 4:30 AM, Philipp Zabel wrote: > > > > Commit cbff8031b491 ("i.MX: clk-pllv3: Do not touch PLL_BYPASS bit") > > > > overreached a bit by removing the code that disables the PLL_BYPASS bit > > > > for all architectures instead of making an exception for Vybrid and > > > > i.MX6SL. This causes the USB controller on i.MX6Q to run at bypass > > > > frequency and fail: > > > > > > > > barebox@Boundary Devices i.MX6 Quad Nitrogen6x Board:/ usb > > > > usb: USB: scanning bus for devices... > > > > usb: Bus 001 Device 001: ID 0000:0000 EHCI Host Controller > > > > imx-usb 2184200.usb: port(0) reset error > > > > > > > > Also, the linux clk-pllv3 driver never looks at or touches the > > > > PLL_BYPASS bit, but expects the bootloader to set it up correctly. > > > > > > > > > > Hmm, wouldn't this code: > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clk/imx/clk-imx6q.c?h=v4.12#n469 > > > > > > alter the state of BYPASS bit? > > > > > > > This patch adds code to unconditionally disable the PLL_BYPASS bit > > > > initially, when the PLL clocks are registered. > > > > > > > > > > The reason I didn't make that patch as a exception for Vybrid and > > > i.MX6SL was because any other i.MX6 clock trees didn't reference that > > > clock mux, so I incorrectly assumed it not to be present in the > > > hardware. IMHO, if this is not the case, a better fix for this would > > > be to change the clock tree to include PLL_BYPASS related mux and call > > > clk_set_parent() explicitly. > > > > > > And having looked at i.MX6Q clock tree code in the kerenel it seems > > > like Barebox version got out of sync and kernel code does create such > > > clock tree node, so maybe we should do that as well? > > > > Possibly, but that's a bigger change than what I would like to pull into > > master and probably a 2017.07 stable. > > I just did a quick whitespace / reordering patch to see what even > changed between barebox and linux (attached below), and there are quite > a few changes, among them the i.MX6Q LDB mux workaround, i.MX6Q/QP > differences in mux paths, the separate PLL bypass muxes, shared gates, > and the i.MX6Q CSCMR1 mux fixup. > > ----------8<---------- > From 9eab6bc893303685554296d6bd8c806ef47fcbe8 Mon Sep 17 00:00:00 2001 > From: Philipp Zabel > Date: Wed, 12 Jul 2017 11:38:00 +0200 > Subject: [PATCH] ARM: i.MX6: align clock driver with linux driver > > This patch changes whitespace, reorders a few definitions, and renames > the clks[] array to clk[] to better align with the linux clk-imx6q > driver. No functional changes. > > Signed-off-by: Philipp Zabel > --- > arch/arm/mach-imx/clk-imx6.c | 592 ++++++++++++++++--------------------------- > 1 file changed, 218 insertions(+), 374 deletions(-) Whoops, wrong code base. I forgot I had to switch to v2016.02 yesterday. Please ignore this patch. regards Philipp _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox