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 4.92.3 #3 (Red Hat Linux)) id 1jltOq-0003Bq-Ke for barebox@lists.infradead.org; Thu, 18 Jun 2020 12:12:09 +0000 From: Sascha Hauer Date: Thu, 18 Jun 2020 14:12:06 +0200 Message-Id: <20200618121206.5013-1-s.hauer@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: [PATCH] Arm: i.MX5: Do not disable L2 cache To: Barebox List Disabling the L2 cache is not working in imx5_init_lowlevel() because the necessary cache maintenance operations are missing. This often results in cache corruption in a chainloaded barebox. Disabling the cache is unnecessary: when we come from the ROM the L2 cache is disabled anyway, so disabling it is a no-op. When we get here in a chainloaded barebox the L2 cache is already enabled and correctly configured. So instead of initializing it again we can take an enabled L2 cache as a sign to skip initialization and just return from the function. Signed-off-by: Sascha Hauer --- arch/arm/mach-imx/imx5.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/arm/mach-imx/imx5.c b/arch/arm/mach-imx/imx5.c index 96288f99e0..dd6c079fe3 100644 --- a/arch/arm/mach-imx/imx5.c +++ b/arch/arm/mach-imx/imx5.c @@ -37,10 +37,13 @@ void imx5_init_lowlevel(void) { u32 r; - /* ARM errata ID #468414 */ __asm__ __volatile__("mrc 15, 0, %0, c1, c0, 1":"=r"(r)); + + if (r & (1 << 1)) + return; + + /* ARM errata ID #468414 */ r |= (1 << 5); /* enable L1NEON bit */ - r &= ~(1 << 1); /* explicitly disable L2 cache */ __asm__ __volatile__("mcr 15, 0, %0, c1, c0, 1" : : "r"(r)); /* reconfigure L2 cache aux control reg */ -- 2.27.0 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox