From mboxrd@z Thu Jan 1 00:00:00 1970 From: minyard@acm.org Subject: [PATCH v2 08/10] i2c-i801: Handle a protocol error in byte-by-byte isr Date: Sun, 29 May 2016 20:09:02 -0500 Message-ID: <1464570544-975-9-git-send-email-minyard@acm.org> References: <1464570544-975-1-git-send-email-minyard@acm.org> Return-path: In-Reply-To: <1464570544-975-1-git-send-email-minyard@acm.org> Sender: linux-kernel-owner@vger.kernel.org To: Jean Delvare , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, minyard@acm.org Cc: Corey Minyard List-Id: linux-i2c@vger.kernel.org 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; wake_up(&priv->waitq); } -- 2.7.4