RE: [PATCH] mei: expand minor range when registering chrdev region
>
> On 2/12/19 5:29 PM, Greg KH wrote:
> > On Tue, Feb 12, 2019 at 02:02:52PM +0800, Chengguang Xu wrote:
> >> Actually, total amount of available minor number for a single major
> >> is MINORMARK + 1. So expand minor range when registering chrdev
> >> region.
> >>
> >> Signed-off-by: Chengguang Xu
> >> ---
> >> drivers/misc/mei/main.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c index
> >> 87281b3695e6..3df54f1e1a8b 100644
> >> --- a/drivers/misc/mei/main.c
> >> +++ b/drivers/misc/mei/main.c
> >> @@ -869,7 +869,7 @@ static const struct file_operations mei_fops = {
> >>
> >> static struct class *mei_class;
> >> static dev_t mei_devt;
> >> -#define MEI_MAX_DEVS MINORMASK
> >> +#define MEI_MAX_DEVS (MINORMASK + 1)
> > Why is this needed? Have you really run out of that many minor nodes
> > for this driver?
>
> Not really, practically maybe we cannot reach to the limit.
> I was just curious why only one minor number left there and assumed that was
> from a mistake(since I've seen similar mistake in other driver).
> However, if it explicitly sets to MINORMASK for some reasons, then it's better
> to keep as is.
I guess this was a boilerplate code, but I'm sure we don't need so many devices.
Thanks
Tomas
Re: [PATCH] mei: expand minor range when registering chrdev region
On 2/12/19 5:29 PM, Greg KH wrote:
On Tue, Feb 12, 2019 at 02:02:52PM +0800, Chengguang Xu wrote:
Actually, total amount of available minor number
for a single major is MINORMARK + 1. So expand
minor range when registering chrdev region.
Signed-off-by: Chengguang Xu
---
drivers/misc/mei/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 87281b3695e6..3df54f1e1a8b 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -869,7 +869,7 @@ static const struct file_operations mei_fops = {
static struct class *mei_class;
static dev_t mei_devt;
-#define MEI_MAX_DEVS MINORMASK
+#define MEI_MAX_DEVS (MINORMASK + 1)
Why is this needed? Have you really run out of that many minor nodes
for this driver?
Not really, practically maybe we cannot reach to the limit.
I was just curious why only one minor number left there and assumed
that was from a mistake(since I've seen similar mistake in other driver).
However, if it explicitly sets to MINORMASK for some reasons, then it's
better to keep as is.
Thanks
Re: [PATCH] mei: expand minor range when registering chrdev region
On Tue, Feb 12, 2019 at 02:02:52PM +0800, Chengguang Xu wrote:
> Actually, total amount of available minor number
> for a single major is MINORMARK + 1. So expand
> minor range when registering chrdev region.
>
> Signed-off-by: Chengguang Xu
> ---
> drivers/misc/mei/main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
> index 87281b3695e6..3df54f1e1a8b 100644
> --- a/drivers/misc/mei/main.c
> +++ b/drivers/misc/mei/main.c
> @@ -869,7 +869,7 @@ static const struct file_operations mei_fops = {
>
> static struct class *mei_class;
> static dev_t mei_devt;
> -#define MEI_MAX_DEVS MINORMASK
> +#define MEI_MAX_DEVS (MINORMASK + 1)
Why is this needed? Have you really run out of that many minor nodes
for this driver?
thanks,
greg k-h
