From 24c7bcb6a74914b529859a07fde27a1a55e13ade Mon Sep 17 00:00:00 2001 From: Alexander Shishkin Date: Fri, 5 Oct 2018 15:42:57 +0300 Subject: [PATCH] stm class: Switch over to the protocol driver Now that the default framing protocol is factored out into its own driver, switch over to using the driver for writing data. To that end, make the policy code require a valid protocol name (or absence thereof, which is equivalent to "p_basic"). Also, to make transition easier, make stm class request "p_basic" module at initialization time. Signed-off-by: Alexander Shishkin Tested-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/stm/core.c | 34 ++++++++++++++++++++-------------- drivers/hwtracing/stm/policy.c | 3 +-- 2 files changed, 21 insertions(+), 16 deletions(-) diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index b789a5f0688e..93ce3aa740a9 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -603,18 +603,21 @@ ssize_t notrace stm_data_write(struct stm_data *data, unsigned int m, } EXPORT_SYMBOL_GPL(stm_data_write); -static ssize_t notrace stm_write(struct stm_data *data, unsigned int master, - unsigned int channel, const char *buf, size_t count) +static ssize_t notrace +stm_write(struct stm_device *stm, struct stm_output *output, + unsigned int chan, const char *buf, size_t count) { - const unsigned char nil = 0; - ssize_t sz; + int err; - sz = stm_data_write(data, master, channel, true, buf, count); - if (sz > 0) - data->packet(data, master, channel, STP_PACKET_FLAG, 0, 0, - &nil); + /* stm->pdrv is serialized against policy_mutex */ + if (!stm->pdrv) + return -ENODEV; - return sz; + err = stm->pdrv->write(stm->data, output, chan, buf, count); + if (err < 0) + return err; + + return err; } static ssize_t stm_char_write(struct file *file, const char __user *buf, @@ -659,8 +662,7 @@ static ssize_t stm_char_write(struct file *file, const char __user *buf, pm_runtime_get_sync(&stm->dev); - count = stm_write(stm->data, stmf->output.master, stmf->output.channel, - kbuf, count); + count = stm_write(stm, &stmf->output, 0, kbuf, count); pm_runtime_mark_last_busy(&stm->dev); pm_runtime_put_autosuspend(&stm->dev); @@ -1310,9 +1312,7 @@ int notrace stm_source_write(struct stm_source_data *data, stm = srcu_dereference(src->link, &stm_source_srcu); if (stm) - count = stm_write(stm->data, src->output.master, - src->output.channel + chan, - buf, count); + count = stm_write(stm, &src->output, chan, buf, count); else count = -ENODEV; @@ -1342,6 +1342,12 @@ static int __init stm_core_init(void) INIT_LIST_HEAD(&stm_pdrv_head); mutex_init(&stm_pdrv_mutex); + /* + * So as to not confuse existing users with a requirement + * to load yet another module, do it here. + */ + if (IS_ENABLED(CONFIG_STM_PROTO_BASIC)) + (void)request_module_nowait("stm_p_basic"); stm_core_up++; return 0; diff --git a/drivers/hwtracing/stm/policy.c b/drivers/hwtracing/stm/policy.c index 8bc90432ae69..5e51bed0787b 100644 --- a/drivers/hwtracing/stm/policy.c +++ b/drivers/hwtracing/stm/policy.c @@ -454,8 +454,7 @@ stp_policy_make(struct config_group *group, const char *name) err = stm_lookup_protocol(proto, &pdrv, &pdrv_node_type); kfree(devname); - /* We don't have any protocol drivers yet */ - if (err != -ENOENT) { + if (err) { stm_put_device(stm); return ERR_PTR(-ENODEV); }