Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751690AbbHJEEP (ORCPT ); Mon, 10 Aug 2015 00:04:15 -0400 Received: from mail-pa0-f47.google.com ([209.85.220.47]:33418 "EHLO mail-pa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750698AbbHJEEJ (ORCPT ); Mon, 10 Aug 2015 00:04:09 -0400 Date: Sun, 9 Aug 2015 21:04:05 -0700 From: Eduardo Valentin To: Fabio Estevam Cc: Greg Kroah-Hartman , Jiri Slaby , Linux PM , "linux-serial@vger.kernel.org" , linux-kernel , Shenwei Wang Subject: Re: [PATCH 5/8] serial: imx: save and restore context in the suspend path Message-ID: <20150810040404.GA5943@localhost.localdomain> References: <1439144349-10494-1-git-send-email-edubezval@gmail.com> <1439144349-10494-6-git-send-email-edubezval@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3647 Lines: 92 On Mon, Aug 10, 2015 at 12:30:18AM -0300, Fabio Estevam wrote: > Hi Eduardo, > > On Sun, Aug 9, 2015 at 3:19 PM, Eduardo Valentin wrote: > > This change teaches the imx serial driver to save its > > context and restore it across suspend and resume path. > > To do so, it introduces serial_imx_restore_context() > > and serial_imx_save_context() functions. They use > > a shadow set of registers to save key registers > > and restore them accordingly. These functions can > > be reused on other situations, when the device > > context is lost. > > > > Cc: Fabio Stevam > > s/Stevam/Estevam (applies to all the patches) Sorry, my bad here. > > > Cc: Greg Kroah-Hartman > > Cc: Jiri Slaby > > Cc: linux-serial@vger.kernel.org > > Cc: linux-kernel@vger.kernel.org > > Signed-off-by: Eduardo Valentin > > --- > > drivers/tty/serial/imx.c | 34 ++++++++++++++++++++++++++++++++++ > > 1 file changed, 34 insertions(+) > > > > diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c > > index a03855d..494b182 100644 > > --- a/drivers/tty/serial/imx.c > > +++ b/drivers/tty/serial/imx.c > > @@ -217,6 +217,8 @@ struct imx_port { > > unsigned int tx_bytes; > > unsigned int dma_tx_nents; > > wait_queue_head_t dma_wait; > > + unsigned int saved_reg[8]; > > + bool context_saved; > > }; > > > > struct imx_port_ucrs { > > @@ -1803,6 +1805,36 @@ static struct uart_driver imx_reg = { > > .cons = IMX_CONSOLE, > > }; > > > > +static void serial_imx_restore_context(struct imx_port *sport) > > +{ > > + if (!sport->context_saved) > > + return; > > + > > + writel(sport->saved_reg[4], sport->port.membase + UFCR); > > + writel(sport->saved_reg[5], sport->port.membase + UBIR); > > + writel(sport->saved_reg[6], sport->port.membase + UBMR); > > + writel(sport->saved_reg[7], sport->port.membase + IMX21_UTS); > > + writel(sport->saved_reg[0], sport->port.membase + UCR1); > > + writel(sport->saved_reg[1] | 0x1, sport->port.membase + UCR2); > > + writel(sport->saved_reg[2], sport->port.membase + UCR3); > > + writel(sport->saved_reg[3], sport->port.membase + UCR4); > > + sport->context_saved = false; > > +} > > + > > +static void serial_imx_save_context(struct imx_port *sport) > > +{ > > + /* Save necessary regs */ > > + sport->saved_reg[0] = readl(sport->port.membase + UCR1); > > + sport->saved_reg[1] = readl(sport->port.membase + UCR2); > > + sport->saved_reg[2] = readl(sport->port.membase + UCR3); > > + sport->saved_reg[3] = readl(sport->port.membase + UCR4); > > + sport->saved_reg[4] = readl(sport->port.membase + UFCR); > > + sport->saved_reg[5] = readl(sport->port.membase + UBIR); > > + sport->saved_reg[6] = readl(sport->port.membase + UBMR); > > + sport->saved_reg[7] = readl(sport->port.membase + IMX21_UTS); > > + sport->context_saved = true; > > +} > > This seems to be similar to what Shenwei posted earlier: > http://lists.infradead.org/pipermail/linux-arm-kernel/2015-July/360841.html OK. Do you know what is the status of that patch set? did it get accepted by any tree so far? > > Regards, > > Fabio Estevam -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/