From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-io1-xd42.google.com ([2607:f8b0:4864:20::d42]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hV9dN-00036k-2C for barebox@lists.infradead.org; Mon, 27 May 2019 07:01:26 +0000 Received: by mail-io1-xd42.google.com with SMTP id r185so7543331iod.6 for ; Mon, 27 May 2019 00:01:24 -0700 (PDT) MIME-Version: 1.0 References: <20190521155626.9906-1-a.fatoum@pengutronix.de> <20190521155626.9906-3-a.fatoum@pengutronix.de> In-Reply-To: <20190521155626.9906-3-a.fatoum@pengutronix.de> From: Andrey Smirnov Date: Mon, 27 May 2019 00:01:12 -0700 Message-ID: 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 v2 2/5] clk: imx6: Make the LDB_DI0 and LDB_DI1 clocks read-only To: Ahmad Fatoum Cc: Barebox List , pza@pengutronix.de On Tue, May 21, 2019 at 8:56 AM Ahmad Fatoum wrote: > > From: Philipp Zabel > > Due to incorrect placement of the clock gate cell in the ldb_di[x]_clk > tree, the glitchy parent mux of ldb_di[x]_clk can cause a glitch to > enter the ldb_di_ipu_div divider. If the divider gets locked up, no > ldb_di[x]_clk is generated, and the LVDS display will hang when the > ipu_di_clk is sourced from ldb_di_clk. > > To fix the problem, both the new and current parent of the ldb_di_clk > should be disabled before the switch. As this can not be guaranteed by > the clock framework during runtime, make the ldb_di[x]_sel muxes read-only. > A workaround to set the muxes once during boot could be added to the > kernel or bootloader. > > Signed-off-by: Philipp Zabel > Signed-off-by: Fabio Estevam > Signed-off-by: Shawn Guo > [afa: ported from Linux kernel commit 03d576f202] > [afa: added exception for i.MX6QP, see kernel commit f4a0a6c309] > [afa: added cpu_has_err009219 helper function] > Signed-off-by: Ahmad Fatoum > --- > drivers/clk/imx/clk-imx6.c | 17 +++++++++++++++-- > drivers/clk/imx/clk.h | 8 ++++++++ > 2 files changed, 23 insertions(+), 2 deletions(-) > > diff --git a/drivers/clk/imx/clk-imx6.c b/drivers/clk/imx/clk-imx6.c > index 319485f8521c..01b649ebbd26 100644 > --- a/drivers/clk/imx/clk-imx6.c > +++ b/drivers/clk/imx/clk-imx6.c > @@ -64,6 +64,12 @@ static inline int cpu_is_plus(void) > return cpu_is_mx6qp() || cpu_is_mx6dp(); > } > > +/* i.MX6 Quad/Dual/DualLite/Solo are all affected */ > +static inline int cpu_has_err009219(void) { That { should really be on a separate line. > + return cpu_is_mx6d() || cpu_is_mx6q() || > + cpu_is_mx6dl() || cpu_is_mx6s(); > +} Hmm, imx_init() is executed at "postcore" and this function will be called at "core" init-level. All of the cpu_is_mx6*() functions will call cpu_is_mx6() which won't work right until imx_init() is called. Are you sure this is working as intended? I think cpu_mx6_is_imx6*() functions should be used instead. That's what I had to do on my board at least. It looks that there's other unrelated code in this file that might have this problem as well. Thanks, Andrey Smirnov _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox