2015-11-02 15:02:22

by Andrew Lunn

[permalink] [raw]
Subject: Re: [PATCH v2 net-next] net: dsa: mv88e6xxx: assert SMI lock

On Fri, Oct 30, 2015 at 06:56:45PM -0400, Vivien Didelot wrote:
> It's easy to forget to lock the smi_mutex before calling the low-level
> _mv88e6xxx_reg_{read,write}, so add a assert_smi_lock function in them.
>
> Signed-off-by: Vivien Didelot <[email protected]>

Acked-by: Andrew Lunn <[email protected]>


Since there is no followup fixes patch, i assume we actually have it
correct at the moment?

Thanks
Andrew

> ---
> drivers/net/dsa/mv88e6xxx.c | 25 ++++++++++++++-----------
> 1 file changed, 14 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
> index b1b14f5..78a179b 100644
> --- a/drivers/net/dsa/mv88e6xxx.c
> +++ b/drivers/net/dsa/mv88e6xxx.c
> @@ -24,6 +24,16 @@
> #include <net/switchdev.h>
> #include "mv88e6xxx.h"
>
> +static void assert_smi_lock(struct dsa_switch *ds)
> +{
> + struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
> +
> + if (unlikely(!mutex_is_locked(&ps->smi_mutex))) {
> + dev_err(ds->master_dev, "SMI lock not held!\n");
> + dump_stack();
> + }
> +}
> +
> /* If the switch's ADDR[4:0] strap pins are strapped to zero, it will
> * use all 32 SMI bus addresses on its SMI bus, and all switch registers
> * will be directly accessible on some {device address,register address}
> @@ -80,12 +90,13 @@ int __mv88e6xxx_reg_read(struct mii_bus *bus, int sw_addr, int addr, int reg)
> return ret & 0xffff;
> }
>
> -/* Must be called with SMI mutex held */
> static int _mv88e6xxx_reg_read(struct dsa_switch *ds, int addr, int reg)
> {
> struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
> int ret;
>
> + assert_smi_lock(ds);
> +
> if (bus == NULL)
> return -EINVAL;
>
> @@ -143,12 +154,13 @@ int __mv88e6xxx_reg_write(struct mii_bus *bus, int sw_addr, int addr,
> return 0;
> }
>
> -/* Must be called with SMI mutex held */
> static int _mv88e6xxx_reg_write(struct dsa_switch *ds, int addr, int reg,
> u16 val)
> {
> struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
>
> + assert_smi_lock(ds);
> +
> if (bus == NULL)
> return -EINVAL;
>
> @@ -204,7 +216,6 @@ int mv88e6xxx_set_addr_indirect(struct dsa_switch *ds, u8 *addr)
> return 0;
> }
>
> -/* Must be called with SMI mutex held */
> static int _mv88e6xxx_phy_read(struct dsa_switch *ds, int addr, int regnum)
> {
> if (addr >= 0)
> @@ -212,7 +223,6 @@ static int _mv88e6xxx_phy_read(struct dsa_switch *ds, int addr, int regnum)
> return 0xffff;
> }
>
> -/* Must be called with SMI mutex held */
> static int _mv88e6xxx_phy_write(struct dsa_switch *ds, int addr, int regnum,
> u16 val)
> {
> @@ -538,7 +548,6 @@ out:
> mutex_unlock(&ps->smi_mutex);
> }
>
> -/* Must be called with SMI mutex held */
> static int _mv88e6xxx_stats_wait(struct dsa_switch *ds)
> {
> int ret;
> @@ -553,7 +562,6 @@ static int _mv88e6xxx_stats_wait(struct dsa_switch *ds)
> return -ETIMEDOUT;
> }
>
> -/* Must be called with SMI mutex held */
> static int _mv88e6xxx_stats_snapshot(struct dsa_switch *ds, int port)
> {
> int ret;
> @@ -576,7 +584,6 @@ static int _mv88e6xxx_stats_snapshot(struct dsa_switch *ds, int port)
> return 0;
> }
>
> -/* Must be called with SMI mutex held */
> static void _mv88e6xxx_stats_read(struct dsa_switch *ds, int stat, u32 *val)
> {
> u32 _val;
> @@ -789,7 +796,6 @@ void mv88e6xxx_get_regs(struct dsa_switch *ds, int port,
> }
> }
>
> -/* Must be called with SMI lock held */
> static int _mv88e6xxx_wait(struct dsa_switch *ds, int reg, int offset,
> u16 mask)
> {
> @@ -839,14 +845,12 @@ int mv88e6xxx_eeprom_busy_wait(struct dsa_switch *ds)
> GLOBAL2_EEPROM_OP_BUSY);
> }
>
> -/* Must be called with SMI lock held */
> static int _mv88e6xxx_atu_wait(struct dsa_switch *ds)
> {
> return _mv88e6xxx_wait(ds, REG_GLOBAL, GLOBAL_ATU_OP,
> GLOBAL_ATU_OP_BUSY);
> }
>
> -/* Must be called with SMI mutex held */
> static int _mv88e6xxx_phy_read_indirect(struct dsa_switch *ds, int addr,
> int regnum)
> {
> @@ -865,7 +869,6 @@ static int _mv88e6xxx_phy_read_indirect(struct dsa_switch *ds, int addr,
> return _mv88e6xxx_reg_read(ds, REG_GLOBAL2, GLOBAL2_SMI_DATA);
> }
>
> -/* Must be called with SMI mutex held */
> static int _mv88e6xxx_phy_write_indirect(struct dsa_switch *ds, int addr,
> int regnum, u16 val)
> {
> --
> 2.6.2
>


2015-11-02 15:10:56

by Vivien Didelot

[permalink] [raw]
Subject: Re: [PATCH v2 net-next] net: dsa: mv88e6xxx: assert SMI lock

Hi Andrew,

On Nov. Monday 02 (45) 04:02 PM, Andrew Lunn wrote:
> On Fri, Oct 30, 2015 at 06:56:45PM -0400, Vivien Didelot wrote:
> > It's easy to forget to lock the smi_mutex before calling the low-level
> > _mv88e6xxx_reg_{read,write}, so add a assert_smi_lock function in them.
> >
> > Signed-off-by: Vivien Didelot <[email protected]>
>
> Acked-by: Andrew Lunn <[email protected]>
>
>
> Since there is no followup fixes patch, i assume we actually have it
> correct at the moment?

Yes, this v2 contains the 2 fixups you mentioned (removing the inline
keyword and keep the dsa_host_dev_to_mii_bus call as is). Thus this
version is correct.

Thanks,
-v

2015-11-02 16:32:22

by Vivien Didelot

[permalink] [raw]
Subject: Re: [PATCH v2 net-next] net: dsa: mv88e6xxx: assert SMI lock

On Nov. Monday 02 (45) 04:02 PM, Andrew Lunn wrote:
> On Fri, Oct 30, 2015 at 06:56:45PM -0400, Vivien Didelot wrote:
> > It's easy to forget to lock the smi_mutex before calling the low-level
> > _mv88e6xxx_reg_{read,write}, so add a assert_smi_lock function in them.
> >
> > Signed-off-by: Vivien Didelot <[email protected]>
>
> Acked-by: Andrew Lunn <[email protected]>
>
>
> Since there is no followup fixes patch, i assume we actually have it
> correct at the moment?

Ho, I just caught what you meant ;-)

>From my (minimal) tests, I didn't see any stack dump yet from setup, FDB
or VLAN operations, looks good so far.

Thanks,
-v