Re: [PATCH v5] drivers/net: process the result of hdlc_open() and add call of hdlc_close() in uhdlc_close()

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 19/09/2023 à 16:25, Alexandra Diupina a écrit :
> Process the result of hdlc_open() and call uhdlc_close()
> in case of an error. It is necessary to pass the error
> code up the control flow, similar to a possible
> error in request_irq().
> Also add a hdlc_close() call to the uhdlc_close()
> because the comment to hdlc_close() says it must be called
> by the hardware driver when the HDLC device is being closed
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: c19b6d246a35 ("drivers/net: support hdlc function for QE-UCC")
> Signed-off-by: Alexandra Diupina <adiupina@astralinux.ru>

Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>

> ---
> v5: do some refactoring as Paolo Abeni <pabeni@redhat.com> and
> Christophe Leroy <christophe.leroy@csgroup.eu> suggested
> v4: undo all the things done prior to hdlc_open() as
> Jakub Kicinski <kuba@kernel.org> suggested,
> add hdlc_close() call to the uhdlc_close() to match the function comment,
> add uhdlc_close() declaration to the top of the file not to put the
> uhdlc_close() function definition before uhdlc_open()
> v3: Fix the commits tree
> v2: Remove the 'rc' variable (stores the return value of the
> hdlc_open()) as Christophe Leroy <christophe.leroy@csgroup.eu> suggested
>   drivers/net/wan/fsl_ucc_hdlc.c | 12 ++++++++++--
>   1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
> index 47c2ad7a3e42..fd50bb313b92 100644
> --- a/drivers/net/wan/fsl_ucc_hdlc.c
> +++ b/drivers/net/wan/fsl_ucc_hdlc.c
> @@ -34,6 +34,8 @@
>   #define TDM_PPPOHT_SLIC_MAXIN
>   #define RX_BD_ERRORS (R_CD_S | R_OV_S | R_CR_S | R_AB_S | R_NO_S | R_LG_S)
>   
> +static int uhdlc_close(struct net_device *dev);
> +
>   static struct ucc_tdm_info utdm_primary_info = {
>   	.uf_info = {
>   		.tsa = 0,
> @@ -708,6 +710,7 @@ static int uhdlc_open(struct net_device *dev)
>   	hdlc_device *hdlc = dev_to_hdlc(dev);
>   	struct ucc_hdlc_private *priv = hdlc->priv;
>   	struct ucc_tdm *utdm = priv->utdm;
> +	int rc = 0;
>   
>   	if (priv->hdlc_busy != 1) {
>   		if (request_irq(priv->ut_info->uf_info.irq,
> @@ -731,10 +734,13 @@ static int uhdlc_open(struct net_device *dev)
>   		napi_enable(&priv->napi);
>   		netdev_reset_queue(dev);
>   		netif_start_queue(dev);
> -		hdlc_open(dev);
> +
> +		rc = hdlc_open(dev);
> +		if (rc)
> +			uhdlc_close(dev);
>   	}
>   
> -	return 0;
> +	return rc;
>   }
>   
>   static void uhdlc_memclean(struct ucc_hdlc_private *priv)
> @@ -824,6 +830,8 @@ static int uhdlc_close(struct net_device *dev)
>   	netdev_reset_queue(dev);
>   	priv->hdlc_busy = 0;
>   
> +	hdlc_close(dev);
> +
>   	return 0;
>   }
>