| Message ID | 1332195985-21043-1-git-send-email-robert.jarzmik@free.fr |
|---|---|
| State | New, archived |
| Headers | show |
Am 19.03.2012 23:26, schrieb Robert Jarzmik: > Add a comment to mtd header for MTD drivers writters, so that they > know that each function in the MTD API, ie. in the mtd_info > structure, is called in a sleeping context. > Why do we need this comment? "sleeping" context isn't special, it's the default. atomic would be... Thanks, //richard
Richard Weinberger <richard@nod.at> writes: > Am 19.03.2012 23:26, schrieb Robert Jarzmik: >> Add a comment to mtd header for MTD drivers writters, so that they >> know that each function in the MTD API, ie. in the mtd_info >> structure, is called in a sleeping context. >> > > Why do we need this comment? Because I was asked to, in [1]. > "sleeping" context isn't special, it's the default. > atomic would be... Ah, well, maybe. From what I've seen in the usb drivers area, portions of code are called from interrupts, through hooks. As a driver writer, I'm always interested to know whether I can msleep() or not. Cheers. -- Robert [1] http://lists.infradead.org/pipermail/linux-mtd/2012-March/040236.html
On Mon, 2012-03-19 at 23:51 +0100, Robert Jarzmik wrote: > Richard Weinberger <richard@nod.at> writes: > > > Am 19.03.2012 23:26, schrieb Robert Jarzmik: > >> Add a comment to mtd header for MTD drivers writters, so that they > >> know that each function in the MTD API, ie. in the mtd_info > >> structure, is called in a sleeping context. > >> > > > > Why do we need this comment? > Because I was asked to, in [1]. Well, Richard has a point :-) But I guess you can simply write "may sleep" instead of "sleeping context". Or may be even use "may_sleep()" in the wrappers?
Artem Bityutskiy <dedekind1@gmail.com> writes: > On Mon, 2012-03-19 at 23:51 +0100, Robert Jarzmik wrote: >> Richard Weinberger <richard@nod.at> writes: >> >> > Am 19.03.2012 23:26, schrieb Robert Jarzmik: >> >> Add a comment to mtd header for MTD drivers writters, so that they >> >> know that each function in the MTD API, ie. in the mtd_info >> >> structure, is called in a sleeping context. >> >> >> > >> > Why do we need this comment? >> Because I was asked to, in [1]. > > Well, Richard has a point :-) Ok ... but I don't get it. I think it's because my previous statement "As a driver writer, I'm always interested to know whether I can msleep() or not." is not good enough ... Neither is my USB example (I was thinking of commit id 5e23e90f33888769ffe253663cc5f3ea0bb6da49 btw). > But I guess you can simply write "may sleep" instead of "sleeping context". Or > may be even use "may_sleep()" in the wrappers? may_sleep() doesn't exist AFAIK. might_sleep() does exist, but it's already mentioned in my patch, and because you're talking about may_sleep() while I used might_sleep(), I'm confused. Do you want me to take my patch and do a simple 's/in a sleeping context/and may sleep/g', or is it more complicated ?
On Wed, 2012-03-21 at 21:20 +0100, Robert Jarzmik wrote: > Do you want me to take my patch and do a simple 's/in a sleeping context/and may > sleep/g', or is it more complicated ? Yes, I guess you can put just a short comment like "these all may sleep". WRT to 'might_sleep()' - you can put these to the _code_, to the mtd wrappers like 'mtd_write()', I suppose.
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index cf5ea8c..4a417e7 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -176,6 +176,11 @@ struct mtd_info { /* * Do not call via these pointers, use corresponding mtd_*() * wrappers instead. + * + * All the following functions are called in a sleeping context, ie. it + * can be safely assumed in mtd drivers that : + * - might_sleep() == 1 + * - msleep(), mutex_lock() and co are authorized */ int (*_erase) (struct mtd_info *mtd, struct erase_info *instr); int (*_point) (struct mtd_info *mtd, loff_t from, size_t len,
Add a comment to mtd header for MTD drivers writters, so that they know that each function in the MTD API, ie. in the mtd_info structure, is called in a sleeping context. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> --- include/linux/mtd/mtd.h | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-)