Linux-i3c Archive on lore.kernel.org
 help / color / Atom feed
From: Vitor Soares <Vitor.Soares@synopsys.com>
To: Boris Brezillon <boris.brezillon@collabora.com>,
	Vitor Soares <Vitor.Soares@synopsys.com>
Cc: "mark.rutland@arm.com" <mark.rutland@arm.com>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"Joao.Pinto@synopsys.com" <Joao.Pinto@synopsys.com>,
	"bbrezillon@kernel.org" <bbrezillon@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"stable@vger.kernel.org" <stable@vger.kernel.org>,
	"pgaj@cadence.com" <pgaj@cadence.com>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>,
	"linux-i3c@lists.infradead.org" <linux-i3c@lists.infradead.org>
Subject: RE: [PATCH v3 2/5] i3c: master: make sure ->boardinfo is initialized in add_i3c_dev_locked()
Date: Thu, 3 Oct 2019 17:37:40 +0000
Message-ID: <CH2PR12MB42162C4459E31D85FD60FB79AE9F0@CH2PR12MB4216.namprd12.prod.outlook.com> (raw)
In-Reply-To: <20191003162943.4a0d0274@collabora.com>

Hi Boris,

From: Boris Brezillon <boris.brezillon@collabora.com>
Date: Thu, Oct 03, 2019 at 15:29:43

> On Thu,  5 Sep 2019 12:00:35 +0200
> Vitor Soares <Vitor.Soares@synopsys.com> wrote:
> 
> > The newdev->boardinfo assignment was missing in
> > i3c_master_add_i3c_dev_locked() and hence the ->of_node info isn't
> > propagated to i3c_dev_desc.
> > 
> > Fix this by trying to initialize device i3c_dev_boardinfo if available.
> > 
> > Cc: <stable@vger.kernel.org>
> > Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure")
> > Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
> > ---
> > Change in v3:
> >   - None
> > 
> > Changes in v2:
> >   - Change commit message
> >   - Change i3c_master_search_i3c_boardinfo(newdev) to
> >   i3c_master_init_i3c_dev_boardinfo(newdev)
> >   - Add fixes, stable tags
> > 
> >  /**
> >   * i3c_master_add_i3c_dev_locked() - add an I3C slave to the bus
> >   * @master: master used to send frames on the bus
> > @@ -1818,8 +1834,9 @@ int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master,
> >  				  u8 addr)
> >  {
> >  	struct i3c_device_info info = { .dyn_addr = addr };
> > -	struct i3c_dev_desc *newdev, *olddev;
> >  	u8 old_dyn_addr = addr, expected_dyn_addr;
> > +	enum i3c_addr_slot_status addrstatus;
> > +	struct i3c_dev_desc *newdev, *olddev;
> >  	struct i3c_ibi_setup ibireq = { };
> >  	bool enable_ibi = false;
> >  	int ret;
> > @@ -1878,6 +1895,8 @@ int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master,
> >  	if (ret)
> >  		goto err_detach_dev;
> >  
> > +	i3c_master_init_i3c_dev_boardinfo(newdev);
> > +
> >  	/*
> >  	 * Depending on our previous state, the expected dynamic address might
> >  	 * differ:
> > @@ -1895,7 +1914,11 @@ int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master,
> >  	else
> >  		expected_dyn_addr = newdev->info.dyn_addr;
> >  
> > -	if (newdev->info.dyn_addr != expected_dyn_addr) {
> > +	addrstatus = i3c_bus_get_addr_slot_status(&master->bus,
> > +						  expected_dyn_addr);
> > +
> > +	if (newdev->info.dyn_addr != expected_dyn_addr &&
> > +	    addrstatus == I3C_ADDR_SLOT_FREE) {
> 
> First, this change shouldn't be part of this patch, since the commit
> message only mentions the boardinfo init stuff,

This is not an issue, I can create a patch just for boardinfo init fix.

> not the extra 'is slot
> free check'.

Even ignoring patch 1, it is necessary to check if the slot is free 
because if SETDASA fails the boardinfo->init_dyn_addr can be assigned to 
another device. That's why we need to check if expected_dyn_addr is free.

> Plus, I want the fix to be backported so we should avoid
> any unneeded deps.
> 
> But even with those 2 things addressed, I'm still convinced the
> 'free desc when device is not reachable' change you do in patch 1 is
> not that great, 

If I'm doing wrong I really appreciate you tell me the reason.

> and the fact that you can't pre-reserve the address to
> make sure no one uses it until the device had a chance to show up tends
> to prove me right.

This is a different corner case and I though we agreed that the framework 
doesn't provide guarantees to assign boardinfo->init_dyn_addr [1].

Yet, I don't disagree with the idea of pre-reserve the 
boardinfo->init_dyn_addr.
I can do this but we need to align how it should be done.

> 
> Can we please do what I suggest and solve the "not enough dev slots"
> problem later on (if we really have to).

I have this use case where the HC has only 4 slot for 4 devices. 
Sometimes the one or more devices can be sleeping and when they trigger 
HJ there is no space in HC.

Best regards,
Vitor Soares

[1] https://patchwork.kernel.org/patch/11120841/

_______________________________________________
linux-i3c mailing list
linux-i3c@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-i3c

  reply index

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-05 10:00 [PATCH v3 0/5] i3c: detach/free device fail pre_assign_dyn_addr() Vitor Soares
2019-09-05 10:00 ` [PATCH v3 1/5] i3c: master: detach/free devices fail on pre_assign_dyn_addr() Vitor Soares
2019-09-17 10:02   ` Vitor Soares
2019-09-05 10:00 ` [PATCH v3 2/5] i3c: master: make sure ->boardinfo is initialized in add_i3c_dev_locked() Vitor Soares
2019-10-03 14:29   ` Boris Brezillon
2019-10-03 17:37     ` Vitor Soares [this message]
2019-10-03 18:35       ` Boris Brezillon
2019-09-05 10:00 ` [PATCH v3 3/5] dt-bindings: i3c: Make 'assigned-address' valid if static address == 0 Vitor Soares
2019-09-05 10:00 ` [PATCH v3 4/5] dt-bindings: i3c: add a note for no guarantee of 'assigned-address' use Vitor Soares
2019-09-05 10:00 ` [PATCH v3 5/5] i3c: master: dw: reattach device on first available location of address table Vitor Soares

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CH2PR12MB42162C4459E31D85FD60FB79AE9F0@CH2PR12MB4216.namprd12.prod.outlook.com \
    --to=vitor.soares@synopsys.com \
    --cc=Joao.Pinto@synopsys.com \
    --cc=bbrezillon@kernel.org \
    --cc=boris.brezillon@collabora.com \
    --cc=devicetree@vger.kernel.org \
    --cc=linux-i3c@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=pgaj@cadence.com \
    --cc=robh+dt@kernel.org \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-i3c Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-i3c/0 linux-i3c/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-i3c linux-i3c/ https://lore.kernel.org/linux-i3c \
		linux-i3c@lists.infradead.org linux-i3c@archiver.kernel.org
	public-inbox-index linux-i3c

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-i3c


AGPL code for this site: git clone https://public-inbox.org/ public-inbox