From patchwork Fri Nov 24 10:41:33 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 747503 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=atomide.com header.i=@atomide.com header.b="t/2H36ys" Received: from mail5.25mail.st (mail5.25mail.st [74.50.62.9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C809D1A8; Fri, 24 Nov 2023 02:42:01 -0800 (PST) Received: from localhost (91-158-86-216.elisa-laajakaista.fi [91.158.86.216]) by mail5.25mail.st (Postfix) with ESMTPSA id 053E6604D9; Fri, 24 Nov 2023 10:41:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=atomide.com; s=25mailst; t=1700822520; bh=EvV+8V5WehTEzKe/Wr+A4+PdH+JfHp240DufQNX02/s=; h=From:To:Cc:Subject:Date:From; b=t/2H36ys8+MpW4QyMj941pP0+/2MD7iURoyzXQIy2sgqgAPQdLvr5BYDS6D2BYThA zn4rrMFdlQcnpQcRJktrFss8wGWC13fMECO+xfUVHSRzHbzjUQst0GqKFt6TtwFMNW 4TU6w8kG+1lmerZ/2kjWsDVCtoH7OX1dXxTYkWyh5kCU9iMaRmUerKB0HrS2cadqrX 0lYAlVKwFxxdxOKMAxlWCCpxlgxSVGwKZDk9baG/oz1eU4OSDmm4Ef6JeOkPgrDyOI FWAgSGRhglCCo+30c1Iz6+qJuda3wURrTII3cEMCMNc+5YJmhnKDpjC95ez+rTLlXq fqwYVZM9VvjGA== From: Tony Lindgren To: linux-omap@vger.kernel.org Cc: Dhruva Gole , Greg Kroah-Hartman , Keerthy , Kevin Hilman , Nishanth Menon , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH] bus: ti-sysc: Flush posted write only after srst_udelay Date: Fri, 24 Nov 2023 12:41:33 +0200 Message-ID: <20231124104133.19100-1-tony@atomide.com> X-Mailer: git-send-email 2.42.1 Precedence: bulk X-Mailing-List: linux-omap@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Commit 34539b442b3b ("bus: ti-sysc: Flush posted write on enable before reset") caused a regression reproducable on omap4 duovero where the ISS target module can produce interconnect errors on boot. Turns out the registers are not accessible until after a delay for devices needing a ti,sysc-delay-us value. Let's fix this by flushing the posted write only after the reset delay. We do flushing also for ti,sysc-delay-us using devices as that should trigger an interconnect error if the delay is not properly configured. Let's also add some comments while at it. Fixes: 34539b442b3b ("bus: ti-sysc: Flush posted write on enable before reset") Signed-off-by: Tony Lindgren --- drivers/bus/ti-sysc.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c --- a/drivers/bus/ti-sysc.c +++ b/drivers/bus/ti-sysc.c @@ -2158,13 +2158,23 @@ static int sysc_reset(struct sysc *ddata) sysc_val = sysc_read_sysconfig(ddata); sysc_val |= sysc_mask; sysc_write(ddata, sysc_offset, sysc_val); - /* Flush posted write */ + + /* + * Some devices need a delay before reading registers + * after reset. Presumably a srst_udelay is not needed + * for devices that use a rstctrl register reset. + */ + if (ddata->cfg.srst_udelay) + fsleep(ddata->cfg.srst_udelay); + + /* + * Flush posted write. For devices needing srst_udelay + * this should trigger an interconnect error if the + * srst_udelay value is needed but not configured. + */ sysc_val = sysc_read_sysconfig(ddata); } - if (ddata->cfg.srst_udelay) - fsleep(ddata->cfg.srst_udelay); - if (ddata->post_reset_quirk) ddata->post_reset_quirk(ddata);