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 4.90_1 #2 (Red Hat Linux)) id 1hVADN-0001pU-MI for barebox@lists.infradead.org; Mon, 27 May 2019 07:38:39 +0000 References: <20190521155626.9906-1-a.fatoum@pengutronix.de> <20190521155626.9906-3-a.fatoum@pengutronix.de> From: Ahmad Fatoum Message-ID: Date: Mon, 27 May 2019 09:38:34 +0200 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US 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: Andrey Smirnov Cc: Barebox List , pza@pengutronix.de Hello Andrey, On 27/5/19 09:01, Andrey Smirnov wrote: > 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 for spotting that. I will send out a v3 with this fixed. > > Thanks, > Andrey Smirnov > -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox