linux-kernel - Re: [PATCH v3 10/11] i3c: master: svc: wait for Manual ACK/NACK Done before next step

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Zsi8td/+4CZSjDbN@lizhi-Precision-Tower-5810>
Date: Fri, 23 Aug 2024 12:45:41 -0400
From: Frank Li <Frank.li@....com>
To: Miquel Raynal <miquel.raynal@...tlin.com>
Cc: Alexandre Belloni <alexandre.belloni@...tlin.com>,
	Boris Brezillon <boris.brezillon@...labora.com>,
	Parshuram Thombare <pthombar@...ence.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Boris Brezillon <bbrezillon@...nel.org>,
	Arnd Bergmann <arnd@...db.de>,
	Conor Culhane <conor.culhane@...vaco.com>,
	linux-i3c@...ts.infradead.org, linux-kernel@...r.kernel.org,
	imx@...ts.linux.dev
Subject: Re: [PATCH v3 10/11] i3c: master: svc: wait for Manual ACK/NACK Done
 before next step

On Fri, Aug 23, 2024 at 06:22:40PM +0200, Miquel Raynal wrote:
> Hi Frank,
>
> Frank.Li@....com wrote on Mon, 19 Aug 2024 12:02:04 -0400:
>
> > Wait for the controller to complete emitting ACK/NACK, otherwise the next
> > command may be omitted by the hardware.
> >
> > Add command done check at svc_i3c_master_nack(ack)_ibi() and change return
>
> 	a "command done" check in
>
> the reutnr type
>
> > type to int to indicate wait done timeout.
>
> 		flag possible timeouts.
>
> >
> > Signed-off-by: Frank Li <Frank.Li@....com>
> > ---
> >  drivers/i3c/master/svc-i3c-master.c | 31 +++++++++++++++++++++++++------
> >  1 file changed, 25 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> > index fbb6cef405577..2010495906eb3 100644
> > --- a/drivers/i3c/master/svc-i3c-master.c
> > +++ b/drivers/i3c/master/svc-i3c-master.c
> > @@ -384,10 +384,12 @@ static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
> >  	return 0;
> >  }
> >
> > -static void svc_i3c_master_ack_ibi(struct svc_i3c_master *master,
> > +static int svc_i3c_master_ack_ibi(struct svc_i3c_master *master,
> >  				   bool mandatory_byte)
> >  {
> >  	unsigned int ibi_ack_nack;
> > +	int ret;
> > +	u32 reg;
> >
> >  	ibi_ack_nack = SVC_I3C_MCTRL_REQUEST_IBI_ACKNACK;
> >  	if (mandatory_byte)
> > @@ -396,18 +398,31 @@ static void svc_i3c_master_ack_ibi(struct svc_i3c_master *master,
> >  		ibi_ack_nack |= SVC_I3C_MCTRL_IBIRESP_ACK_WITHOUT_BYTE;
> >
> >  	writel(ibi_ack_nack, master->regs + SVC_I3C_MCTRL);
> > +
> > +	ret = readl_poll_timeout_atomic(master->regs + SVC_I3C_MSTATUS, reg,
> > +					SVC_I3C_MSTATUS_MCTRLDONE(reg), 1, 1000);
>
> Still concerned about the _atomic.

It may be call in atomic context. Because hardware design limition, i3c
transact have been in irq disable context to avoid 100us timeout issue.

Frank

>
> > +	return ret;
>
> 	return readl...
>
> > +
> >  }
>
> Otherwise LGTM
>
> Reviewed-by: Miquel Raynal <miquel.raynal@...tlin.com>
>
> Thanks,
> Miquèl