Re: [PATCH v3 2/6] i3c: master: svc: fix wrong data return when IBI happen during start frame

From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Frank Li <Frank.Li@nxp.com>
Cc: alexandre.belloni@bootlin.com, conor.culhane@silvaco.com,
	imx@lists.linux.dev, joe@perches.com,
	linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/6] i3c: master: svc: fix wrong data return when IBI happen during start frame
Date: Fri, 20 Oct 2023 15:56:03 +0200	[thread overview]
Message-ID: <20231020155603.52cc7206@xps-13> (raw)
In-Reply-To: <20231019222725.3598022-3-Frank.Li@nxp.com>

Hi Frank,

Frank.Li@nxp.com wrote on Thu, 19 Oct 2023 18:27:21 -0400:

>      ┌─────┐     ┏──┐  ┏──┐  ┏──┐  ┏──┐  ┏──┐  ┏──┐  ┏──┐  ┏──┐  ┌─────
> SCL: ┘     └─────┛  └──┛  └──┛  └──┛  └──┛  └──┛  └──┛  └──┛  └──┘
>      ───┐                       ┌─────┐     ┌─────┐     ┌───────────┐
> SDA:    └───────────────────────┘     └─────┘     └─────┘           └─────
>      xxx╱    ╲╱                                        ╲╱    ╲╱    ╲╱    ╲
>    : xxx╲IBI ╱╲               Addr(0x0a)               ╱╲ RW ╱╲NACK╱╲ S  ╱
> 
> If an In-Band Interrupt (IBI) occurs and IBI work thread is not immediately
> scheduled, When svc_i3c_master_priv_xfers() initiates the I3C transfer and

nit:		when

> attempts to send address 0x7e, the target interprets it as an
> IBI handler and returns the target address 0x0a.
> 
> However, svc_i3c_master_priv_xfers() does not handle this case and proceeds
> with other transfers, resulting in incorrect data being returned.
> 
> Add IBIWON check in svc_i3c_master_xfer(). In case this situation occurs,
> return a failure to the driver.
> 
> Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
> Cc: stable@vger.kernel.org
> Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---

Thanks,
Miquèl

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