From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB1C5C5ACD6 for ; Wed, 18 Mar 2020 14:38:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF32720773 for ; Wed, 18 Mar 2020 14:38:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584542314; bh=ruUacygRA1pYuADNBjr/rlPAjaaGReif+YMpRHqema4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=t55GaoSwYJKtcZYbqzcyw05kXQ0aPyyMyyzf8T9BXQzP8gube6duTin0zRBKQm72C oPOoegKzLpYLhdcmiWytQR3AtV9iWAaACVIqJg1F6bhol0UXtiR8pQ9DreFlk0X0Ce Y0JUgu0gmcYfKTZp4b8uHME6BfYwKIf4NkW8ZC+o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726813AbgCROia (ORCPT ); Wed, 18 Mar 2020 10:38:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:53590 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726643AbgCROia (ORCPT ); Wed, 18 Mar 2020 10:38:30 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6B23E20770; Wed, 18 Mar 2020 14:38:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584542308; bh=ruUacygRA1pYuADNBjr/rlPAjaaGReif+YMpRHqema4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=obwKPMMwxgm26AkB2TdPXJf0rWoAu8a2wvzMukGG49p3Xnp91RXX+4ZxD2kK6FRsu bPBTIq+2AeL6FmIR9E/qzMp4OWXZjg1/DPHUTqyWfQDDuYkMFh4bk1fvoHEa5bHiN7 5deHfj3boMLUCD8MQ5+GcXbhSglqi5AQGgB5aP6M= Date: Wed, 18 Mar 2020 15:38:26 +0100 From: Greg KH To: Manivannan Sadhasivam Cc: Jeffrey Hugo , arnd@arndb.de, smohanad@codeaurora.org, kvalo@codeaurora.org, bjorn.andersson@linaro.org, hemantk@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 03/16] bus: mhi: core: Add support for registering MHI client drivers Message-ID: <20200318143826.GA2809114@kroah.com> References: <20200220095854.4804-1-manivannan.sadhasivam@linaro.org> <20200220095854.4804-4-manivannan.sadhasivam@linaro.org> <20200318133626.GA2801580@kroah.com> <20200318140034.GA2805201@kroah.com> <20200318142312.GA11494@Mani-XPS-13-9360> <20200318142730.GB2807628@kroah.com> <20200318143145.GA12341@Mani-XPS-13-9360> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200318143145.GA12341@Mani-XPS-13-9360> Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Wed, Mar 18, 2020 at 08:01:45PM +0530, Manivannan Sadhasivam wrote: > On Wed, Mar 18, 2020 at 03:27:30PM +0100, Greg KH wrote: > > On Wed, Mar 18, 2020 at 07:53:12PM +0530, Manivannan Sadhasivam wrote: > > > Hi Greg, > > > > > > On Wed, Mar 18, 2020 at 03:00:34PM +0100, Greg KH wrote: > > > > On Wed, Mar 18, 2020 at 07:54:30AM -0600, Jeffrey Hugo wrote: > > > > > On 3/18/2020 7:36 AM, Greg KH wrote: > > > > > > On Thu, Feb 20, 2020 at 03:28:41PM +0530, Manivannan Sadhasivam wrote: > > > > > > > This commit adds support for registering MHI client drivers with the > > > > > > > MHI stack. MHI client drivers binds to one or more MHI devices inorder > > > > > > > to sends and receive the upper-layer protocol packets like IP packets, > > > > > > > modem control messages, and diagnostics messages over MHI bus. > > > > > > > > > > > > > > This is based on the patch submitted by Sujeev Dias: > > > > > > > https://lkml.org/lkml/2018/7/9/987 > > > > > > > > > > > > > > Signed-off-by: Sujeev Dias > > > > > > > Signed-off-by: Siddartha Mohanadoss > > > > > > > [mani: splitted and cleaned up for upstream] > > > > > > > Signed-off-by: Manivannan Sadhasivam > > > > > > > Reviewed-by: Jeffrey Hugo > > > > > > > Tested-by: Jeffrey Hugo > > > > > > > --- > > > > > > > drivers/bus/mhi/core/init.c | 149 ++++++++++++++++++++++++++++++++++++ > > > > > > > include/linux/mhi.h | 39 ++++++++++ > > > > > > > 2 files changed, 188 insertions(+) > > > > > > > > > > > > > > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c > > > > > > > index 6f24c21284ec..12e386862b3f 100644 > > > > > > > --- a/drivers/bus/mhi/core/init.c > > > > > > > +++ b/drivers/bus/mhi/core/init.c > > > > > > > @@ -374,8 +374,157 @@ struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl) > > > > > > > return mhi_dev; > > > > > > > } > > > > > > > +static int mhi_driver_probe(struct device *dev) > > > > > > > +{ > > > > > > > + struct mhi_device *mhi_dev = to_mhi_device(dev); > > > > > > > + struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl; > > > > > > > + struct device_driver *drv = dev->driver; > > > > > > > + struct mhi_driver *mhi_drv = to_mhi_driver(drv); > > > > > > > + struct mhi_event *mhi_event; > > > > > > > + struct mhi_chan *ul_chan = mhi_dev->ul_chan; > > > > > > > + struct mhi_chan *dl_chan = mhi_dev->dl_chan; > > > > > > > + > > > > > > > + if (ul_chan) { > > > > > > > + /* > > > > > > > + * If channel supports LPM notifications then status_cb should > > > > > > > + * be provided > > > > > > > + */ > > > > > > > + if (ul_chan->lpm_notify && !mhi_drv->status_cb) > > > > > > > + return -EINVAL; > > > > > > > + > > > > > > > + /* For non-offload channels then xfer_cb should be provided */ > > > > > > > + if (!ul_chan->offload_ch && !mhi_drv->ul_xfer_cb) > > > > > > > + return -EINVAL; > > > > > > > + > > > > > > > + ul_chan->xfer_cb = mhi_drv->ul_xfer_cb; > > > > > > > + } > > > > > > > + > > > > > > > + if (dl_chan) { > > > > > > > + /* > > > > > > > + * If channel supports LPM notifications then status_cb should > > > > > > > + * be provided > > > > > > > + */ > > > > > > > + if (dl_chan->lpm_notify && !mhi_drv->status_cb) > > > > > > > + return -EINVAL; > > > > > > > + > > > > > > > + /* For non-offload channels then xfer_cb should be provided */ > > > > > > > + if (!dl_chan->offload_ch && !mhi_drv->dl_xfer_cb) > > > > > > > + return -EINVAL; > > > > > > > + > > > > > > > + mhi_event = &mhi_cntrl->mhi_event[dl_chan->er_index]; > > > > > > > + > > > > > > > + /* > > > > > > > + * If the channel event ring is managed by client, then > > > > > > > + * status_cb must be provided so that the framework can > > > > > > > + * notify pending data > > > > > > > + */ > > > > > > > + if (mhi_event->cl_manage && !mhi_drv->status_cb) > > > > > > > + return -EINVAL; > > > > > > > + > > > > > > > + dl_chan->xfer_cb = mhi_drv->dl_xfer_cb; > > > > > > > + } > > > > > > > + > > > > > > > + /* Call the user provided probe function */ > > > > > > > + return mhi_drv->probe(mhi_dev, mhi_dev->id); > > > > > > > +} > > > > > > > + > > > > > > > +static int mhi_driver_remove(struct device *dev) > > > > > > > +{ > > > > > > > + struct mhi_device *mhi_dev = to_mhi_device(dev); > > > > > > > + struct mhi_driver *mhi_drv = to_mhi_driver(dev->driver); > > > > > > > + struct mhi_chan *mhi_chan; > > > > > > > + enum mhi_ch_state ch_state[] = { > > > > > > > + MHI_CH_STATE_DISABLED, > > > > > > > + MHI_CH_STATE_DISABLED > > > > > > > + }; > > > > > > > + int dir; > > > > > > > + > > > > > > > + /* Skip if it is a controller device */ > > > > > > > + if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER) > > > > > > > + return 0; > > > > > > > + > > > > > > > + /* Reset both channels */ > > > > > > > + for (dir = 0; dir < 2; dir++) { > > > > > > > + mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan; > > > > > > > + > > > > > > > + if (!mhi_chan) > > > > > > > + continue; > > > > > > > + > > > > > > > + /* Wake all threads waiting for completion */ > > > > > > > + write_lock_irq(&mhi_chan->lock); > > > > > > > + mhi_chan->ccs = MHI_EV_CC_INVALID; > > > > > > > + complete_all(&mhi_chan->completion); > > > > > > > + write_unlock_irq(&mhi_chan->lock); > > > > > > > + > > > > > > > + /* Set the channel state to disabled */ > > > > > > > + mutex_lock(&mhi_chan->mutex); > > > > > > > + write_lock_irq(&mhi_chan->lock); > > > > > > > + ch_state[dir] = mhi_chan->ch_state; > > > > > > > + mhi_chan->ch_state = MHI_CH_STATE_SUSPENDED; > > > > > > > + write_unlock_irq(&mhi_chan->lock); > > > > > > > + > > > > > > > + mutex_unlock(&mhi_chan->mutex); > > > > > > > + } > > > > > > > + > > > > > > > + mhi_drv->remove(mhi_dev); > > > > > > > + > > > > > > > + /* De-init channel if it was enabled */ > > > > > > > + for (dir = 0; dir < 2; dir++) { > > > > > > > + mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan; > > > > > > > + > > > > > > > + if (!mhi_chan) > > > > > > > + continue; > > > > > > > + > > > > > > > + mutex_lock(&mhi_chan->mutex); > > > > > > > + > > > > > > > + mhi_chan->ch_state = MHI_CH_STATE_DISABLED; > > > > > > > + > > > > > > > + mutex_unlock(&mhi_chan->mutex); > > > > > > > + } > > > > > > > + > > > > > > > + return 0; > > > > > > > +} > > > > > > > + > > > > > > > +int mhi_driver_register(struct mhi_driver *mhi_drv) > > > > > > > +{ > > > > > > > + struct device_driver *driver = &mhi_drv->driver; > > > > > > > + > > > > > > > + if (!mhi_drv->probe || !mhi_drv->remove) > > > > > > > + return -EINVAL; > > > > > > > + > > > > > > > + driver->bus = &mhi_bus_type; > > > > > > > + driver->probe = mhi_driver_probe; > > > > > > > + driver->remove = mhi_driver_remove; > > > > > > > + > > > > > > > + return driver_register(driver); > > > > > > > +} > > > > > > > +EXPORT_SYMBOL_GPL(mhi_driver_register); > > > > > > > > > > > > You don't care about module owners of the driver? Odd :( > > > > > > > > > > > > (hint, you probably should...) > > > > > > > > > > > > greg k-h > > > > > > > > > > > > > > > > For my own education, can you please clarify your comment? I'm not sure > > > > > that I understand the context of what you are saying (ie why is this export > > > > > a possible problem?). > > > > > > > > Sorry, it didn't have to do with the export, it had to do with the fact > > > > that your driver_register() function does not pass in the owner of the > > > > module of the driver, like almost all other subsystems do. That way you > > > > can try to protect the module from being unloaded if it has files open > > > > assigned to it. > > > > > > > > If you don't have any userspace accesses like that, to the driver, then > > > > nevermind, all is fine :) > > > > > > > > > > This is not needed right now but I'll fix this anyway to avoid issues in > > > future :) > > > > > > Btw, may I know the status of this series? Do you have any more comments > > > or do you happen to wait for more reviews? > > > > It would be nice to get other reviews, but other than what I noticed > > above, it looks sane to me. Am I the one supposed to take these > > patches? > > > > I guess so ;) Do you think I need to sent another revision incorporating > the module owner fix or it can come as an incremental patch? Btw, I do > have few more in pipeline :) I'll just go take these now and you can send a follow-on patch for the module owner. Let's see if 0-day complains about it :) thanks, greg k-h