Hey Alex,
Have a look at the following patch and see if you agree with my approach. If so
simply add the code to a third version.
Thanks,
Mathieu
>From 70b4709b668ef59b303dabeff73ed850a4980cfc Mon Sep 17 00:00:00 2001
From: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Date: Thu, 26 Mar 2015 15:33:03 -0600
Subject: [PATCH] stm class: Adding master and channel parameter to ioctl
function
Just like the "write" function, architecture specific device need
to know about master and channels to do the correct operations on
a ioctl call.
Since this information is embedded in the stm_file structure that
is private to the stm class core, adding extra parameters to convey
the values is simple and clean.
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
drivers/hwtracing/stm/core.c | 12 ++++++++++--
include/linux/stm.h | 5 +++--
2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index 9e82634590dc..ca71b06bbfea 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -511,9 +511,17 @@ stm_char_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
return stm_char_policy_get_ioctl(stmf, (void __user *)arg);
default:
- if (stm_data->ioctl)
- err = stm_data->ioctl(stm_data, cmd, arg);
+ if (stm_data->ioctl) {
+ /* users shouldn't call device specific ioctl before
+ * getting a channel using the proper potocol
+ */
+ if (!stmf->output.nr_chans)
+ return -EINVAL;
+ err = stm_data->ioctl(stm_data, stmf->output.master,
+ stmf->output.channel, cmd, arg);
+
+ }
break;
}
diff --git a/include/linux/stm.h b/include/linux/stm.h
index 976c94d8f17f..84dd83c47fe7 100644
--- a/include/linux/stm.h
+++ b/include/linux/stm.h
@@ -62,8 +62,9 @@ struct stm_data {
unsigned int);
void (*unlink)(struct stm_data *, unsigned int,
unsigned int);
- long (*ioctl)(struct stm_data *, unsigned int,
- unsigned long);
+ long (*ioctl)(struct stm_data *,
+ unsigned int, unsigned int,
+ unsigned int, unsigned long);
};
int stm_register_device(struct device *parent, struct stm_data *stm_data,
--
1.9.1
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