From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Tissoires Subject: Re: [v2,08/10] i2c-i801: Handle a protocol error in byte-by-byte isr Date: Thu, 9 Jun 2016 16:07:57 +0200 Message-ID: <20160609140748.GJ24234@mail.corp.redhat.com> References: <1464570544-975-9-git-send-email-minyard@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:54657 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751393AbcFIOIC (ORCPT ); Thu, 9 Jun 2016 10:08:02 -0400 Content-Disposition: inline In-Reply-To: <1464570544-975-9-git-send-email-minyard@acm.org> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: Corey Minyard Cc: Jean Delvare , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Corey Minyard On May 29 2016 or thereabouts, Corey Minyard wrote: > From: Corey Minyard > > If a bad number of bytes is read on a transaction, have it > report an error and return -EPROTO for the transaction. > > Signed-off-by: Corey Minyard > --- > drivers/i2c/busses/i2c-i801.c | 27 ++++++++++++++++----------- > 1 file changed, 16 insertions(+), 11 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c > index b415948..70da60a 100644 > --- a/drivers/i2c/busses/i2c-i801.c > +++ b/drivers/i2c/busses/i2c-i801.c > @@ -230,7 +230,7 @@ struct i801_priv { > > /* isr processing */ > wait_queue_head_t waitq; > - u8 status; > + int status; > > /* Command state used by isr for byte-by-byte block transactions */ > u8 subcmd; > @@ -472,16 +472,18 @@ static void i801_isr_byte_done(struct i801_priv *priv) > (priv->count == 0)) { > priv->len = inb_p(SMBHSTDAT0(priv)); > if (priv->len < 1 || priv->len > I2C_SMBUS_BLOCK_MAX) { > - dev_err(&priv->pci_dev->dev, > - "Illegal SMBus block read size %d\n", > - priv->len); > - /* FIXME: Recover */ > - priv->len = I2C_SMBUS_BLOCK_MAX; > - } else { > - dev_dbg(&priv->pci_dev->dev, > - "SMBus block read size is %d\n", > - priv->len); > + /* > + * Terminate the transaction here, to avoid > + * getting any more interrupts that might > + * hold us in an interrupt loop forever. > + */ > + outb_p(inb_p(SMBHSTCNT(priv)) | SMBHSTCNT_KILL, > + SMBHSTCNT(priv)); > + priv->status = -EPROTO; > + return; > } > + dev_dbg(&priv->pci_dev->dev, > + "SMBus block read size is %d\n", priv->len); > priv->data[-1] = priv->len; > } > > @@ -541,7 +543,10 @@ static irqreturn_t i801_isr(int irq, void *dev_id) > status &= SMBHSTSTS_INTR | STATUS_ERROR_FLAGS; > if (status) { > outb_p(status, SMBHSTSTS(priv)); > - priv->status |= status; > + if (status < 0) > + priv->status = status; > + else > + priv->status |= status; This hunk conflicts with http://patchwork.ozlabs.org/patch/626051/ and could be removed if this mentioned patch is applied first. The rest of the patch looks OK to me. Cheers, Benjamin > wake_up(&priv->waitq); > } >