lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 3 Dec 2019 10:23:57 -0500 (EST) From: Alan Stern <stern@...land.harvard.edu> To: Ikjoon Jang <ikjn@...omium.org> cc: linux-usb@...r.kernel.org, GregKroah-Hartman <gregkh@...uxfoundation.org>, RobHerring <robh+dt@...nel.org>, MarkRutland <mark.rutland@....com>, SuwanKim <suwan.kim027@...il.com>, "GustavoA . R . Silva" <gustavo@...eddedor.com>, JohanHovold <johan@...nel.org>, <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>, <drinkcat@...omium.org> Subject: Re: [PATCH v4 2/2] usb: overridable hub bInterval by device node On Tue, 3 Dec 2019, Ikjoon Jang wrote: > This patch enables hub device to override its own endpoint descriptor's > bInterval when the hub has a device node with "hub,interval" property. > > When we know reducing autosuspend delay for built-in HIDs is better for > power saving, we can reduce it to the optimal value. But if a parent hub > has a long bInterval, mouse lags a lot from more frequent autosuspend. > So this enables overriding bInterval for a hard wired hub device only > when we know that reduces the power consumption. > > Signed-off-by: Ikjoon Jang <ikjn@...omium.org> > Acked-by: Alan Stern <stern@...land.harvard.edu> > --- > drivers/usb/core/config.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c > index 5f40117e68e7..95ec5af42a1c 100644 > --- a/drivers/usb/core/config.c > +++ b/drivers/usb/core/config.c > @@ -6,6 +6,7 @@ > #include <linux/usb.h> > #include <linux/usb/ch9.h> > #include <linux/usb/hcd.h> > +#include <linux/usb/of.h> > #include <linux/usb/quirks.h> > #include <linux/module.h> > #include <linux/slab.h> > @@ -257,6 +258,14 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, > memcpy(&endpoint->desc, d, n); > INIT_LIST_HEAD(&endpoint->urb_list); > > + /* device node property overrides bInterval */ > + if (usb_of_has_combined_node(to_usb_device(ddev))) { > + u32 interval = 0; Coding style: there should be a blank line here. Also, you don't need the "= 0" initializer. Otherwise okay. Alan Stern > + if (!of_property_read_u32(ddev->of_node, "hub,interval", > + &interval)) > + d->bInterval = min_t(u8, interval, 255); > + } > + > /* > * Fix up bInterval values outside the legal range. > * Use 10 or 8 ms if no proper value can be guessed.
Powered by blists - more mailing lists