From e5617d2bf5492aea96cb99cc772aded46804add3 Mon Sep 17 00:00:00 2001 From: Alexander Usyskin Date: Tue, 18 Aug 2020 14:51:43 +0300 Subject: [PATCH] mei: bus: use zero vtag for bus clients. The zero vtag is required for the read flow to work also for devices on the mei client bus. Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Link: https://lore.kernel.org/r/20200818115147.2567012-10-tomas.winkler@intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/bus.c | 72 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 71 insertions(+), 1 deletion(-) diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c index fc20a0da5c24f..9cdaa7f3af235 100644 --- a/drivers/misc/mei/bus.c +++ b/drivers/misc/mei/bus.c @@ -495,6 +495,68 @@ static void mei_cl_bus_module_put(struct mei_cl_device *cldev) module_put(cldev->bus->dev->driver->owner); } +/** + * mei_cl_bus_vtag - get bus vtag entry wrapper + * The tag for bus client is always first. + * + * @cl: host client + * + * Return: bus vtag or NULL + */ +static inline struct mei_cl_vtag *mei_cl_bus_vtag(struct mei_cl *cl) +{ + return list_first_entry_or_null(&cl->vtag_map, + struct mei_cl_vtag, list); +} + +/** + * mei_cl_bus_vtag_alloc - add bus client entry to vtag map + * + * @cldev: me client device + * + * Return: + * * 0 on success + * * -ENOMEM if memory allocation failed + */ +static int mei_cl_bus_vtag_alloc(struct mei_cl_device *cldev) +{ + struct mei_cl *cl = cldev->cl; + struct mei_cl_vtag *cl_vtag; + + /* + * Bail out if the client does not supports vtags + * or has already allocated one + */ + if (mei_cl_vt_support_check(cl) || mei_cl_bus_vtag(cl)) + return 0; + + cl_vtag = mei_cl_vtag_alloc(NULL, 0); + if (IS_ERR(cl_vtag)) + return -ENOMEM; + + list_add_tail(&cl_vtag->list, &cl->vtag_map); + + return 0; +} + +/** + * mei_cl_bus_vtag_free - remove the bus entry from vtag map + * + * @cldev: me client device + */ +static void mei_cl_bus_vtag_free(struct mei_cl_device *cldev) +{ + struct mei_cl *cl = cldev->cl; + struct mei_cl_vtag *cl_vtag; + + cl_vtag = mei_cl_bus_vtag(cl); + if (!cl_vtag) + return; + + list_del(&cl_vtag->list); + kfree(cl_vtag); +} + /** * mei_cldev_enable - enable me client device * create connection with me client @@ -531,9 +593,15 @@ int mei_cldev_enable(struct mei_cl_device *cldev) goto out; } + ret = mei_cl_bus_vtag_alloc(cldev); + if (ret) + goto out; + ret = mei_cl_connect(cl, cldev->me_cl, NULL); - if (ret < 0) + if (ret < 0) { dev_err(&cldev->dev, "cannot connect\n"); + mei_cl_bus_vtag_free(cldev); + } out: mutex_unlock(&bus->device_lock); @@ -586,6 +654,8 @@ int mei_cldev_disable(struct mei_cl_device *cldev) mutex_lock(&bus->device_lock); + mei_cl_bus_vtag_free(cldev); + if (!mei_cl_is_connected(cl)) { dev_dbg(bus->dev, "Already disconnected\n"); err = 0; -- 2.30.2