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charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: DM4PR12MB7765.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 81b9860a-15cf-45d5-6104-08db926a0dfd X-MS-Exchange-CrossTenant-originalarrivaltime: 01 Aug 2023 08:34:00.1490 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: Fh/6o/cHlRy8kDeq20hM8zl2AK/M8QxlzH0uqxqMTwwqiENx1iTQYw7HbzlGmirxWebB8Bcn+RZPwJcMCPK4jA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW6PR12MB8959 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > From: Greg KH > Sent: Monday, July 31, 2023 5:55 PM > To: Gangurde, Abhijit > Cc: masahiroy@kernel.org; linux-kernel@vger.kernel.org; Simek, Michal > ; git (AMD-Xilinx) ; Agarwal, Nikhil > ; Gupta, Nipun > Subject: Re: [PATCH v2 1/4] cdx: Introduce lock to protect controller ops= and > controller list >=20 > On Mon, Jul 31, 2023 at 05:38:10PM +0530, Abhijit Gangurde wrote: > > Add a mutex lock to prevent race between controller ops initiated by > > the bus subsystem and the controller registration/unregistration. > > > > Signed-off-by: Abhijit Gangurde > > --- > > drivers/cdx/cdx.c | 14 ++++++++++++++ > > 1 file changed, 14 insertions(+) > > > > diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c > > index d2cad4c670a0..66797c8fe400 100644 > > --- a/drivers/cdx/cdx.c > > +++ b/drivers/cdx/cdx.c > > @@ -72,6 +72,8 @@ > > > > /* CDX controllers registered with the CDX bus */ > > static DEFINE_XARRAY_ALLOC(cdx_controllers); > > +/* Lock to protect controller ops and controller list */ > > +static DEFINE_MUTEX(cdx_controller_lock); >=20 > Wait, why do you have a local list and not just rely on the list the > driver core has for you already? Isn't this a duplicate list where you > have objects on two different lists with a lifespan controlled only by > one of them? cdx_controllers list is holding just the controllers registered on the cdx = bus system. CDX devices are still maintained by driver core list. Controller list is us= ed by rescan which triggers rescan on all the controllers. Thanks, Abhijit