On Fri, 17 Oct 2014 12:53:45 -0400 (EDT) Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Fri, 17 Oct 2014, Mark Knibbs wrote: > > > In include/linux/usb.h, there is > > /* > > * timeouts, in milliseconds, used for sending/receiving control messages > > * they typically complete within a few frames (msec) after they're issued > > * USB identifies 5 second timeouts, maybe more in a few cases, and a few > > * slow devices (like some MGE Ellipse UPSes) actually push that limit. > > */ > > #define USB_CTRL_GET_TIMEOUT 5000 > > #define USB_CTRL_SET_TIMEOUT 5000 > > Those timeout values are used with usb_control_msg(), which takes > timeout values in milliseconds. > > > However several callers of usb_stor_control_msg() have timeout argument > > specified as n*HZ, for example in drivers/usb/storage/transport.c: > > ... > > This is because usb_stor_control_msg accepts timeout values in jiffies. > > > I'm just wondering whether those callers should have timeouts in ms (so > > 3*HZ -> 3000), or whether the definitions of USB_CTRL_GET/SET_TIMEOUT > > should be 5*HZ? Or is HZ always 1000 these days? > > No, no, and no. Ah, thanks. Given that, it seems my recent patch "[PATCH] storage: Replace magic number with define in usb_stor_euscsi_init()" which replaced 5000 with USB_CTRL_SET_TIMEOUT wasn't correct, though that patch wouldn't change the compiled code. It looks like the 5000 timeout in usb_stor_euscsi_init() should be replaced by 5*HZ then? Mark -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
