On Fri, Jan 10, 2014 at 10:31:05AM +0800, Peter Chen wrote: > On Thu, Jan 09, 2014 at 10:53:45AM +0100, Marc Kleine-Budde wrote: > > On 01/09/2014 04:22 AM, Greg KH wrote: > > > On Thu, Jan 09, 2014 at 09:36:09AM +0800, Peter Chen wrote: > > >> On Tue, Jan 07, 2014 at 04:20:25PM -0800, Greg KH wrote: > > >>> On Mon, Jan 06, 2014 at 09:42:26AM +0100, Marc Kleine-Budde wrote: > > >>>> Hello Peter and Greg, > > >>>> > > >>>> On 01/06/2014 03:10 AM, Peter Chen wrote: > > >>>>> According to Freescale imx28 Errata, "ENGR119653 USB: ARM to USB > > >>>>> register error issue", All USB register write operations must > > >>>>> use the ARM SWP instruction. So, we implement a special ehci_write > > >>>>> for imx28. > > >>>>> > > >>>>> Discussion for it at below: > > >>>>> http://marc.info/?l=linux-usb&m=137996395529294&w=2 > > >>>>> > > >>>>> Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx> > > >>>>> Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > >>>>> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> > > >>>>> Tested-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> > > >>>> > > >>>> please add stable on Cc for this and the next two patches: > > >>>> > > >>>> [PATCH 4/8] usb: ehci: add freescale imx28 special write register method > > >>>> [PATCH 5/8] usb: chipidea: add freescale imx28 special write register method > > >>>> [PATCH 6/8] usb: chipidea: imx: set CI_HDRC_IMX28_WRITE_FIX for imx28 > > >>> > > >>> How do those patches meet the Documentation/stable_kernel_rules.txt > > >>> guidelines? > > >>> > > >>> > > >> > > >> - It must be obviously correct and tested. > > >> It has Marc Kleine-Budde's tested-by tag. > > >> > > >> - It cannot be bigger than 100 lines, with context. > > >> I think it is. > > >> > > >> - It must fix only one thing. > > >> It only fixes the imx28 special write problem. > > >> > > >> - It must fix a real bug that bothers people (not a, "This could be a > > >> problem..." type thing). > > >> Robert Hodaszi reported this problem at below link: > > >> http://marc.info/?l=linux-usb&m=137996395529294&w=2 > > > > > > You are adding new functionality for something that never worked before > > > (i.e. new features), which is not ok for stable kernel patches, with the > > > exception of new quirks or device ids. > > > > > > sorry, this is something new, not a stable kernel patch. > > > > Without this fix, the mx28 works...most of the time. However under > > certain load scenarios the driver breaks. This is, IMHO, a fix. > > > > Without this patcheset, imx28 works unstable at high AHB bus loading. > If the bus loading is not high, the imx28 usb can work well at the most > of time. There is a IC errata for this problem, usually, we consider > IC errata is a problem not a new feature, and this workaround is needed > for that. > > We need three patches to fix this problem for both host and peripheral > mode and limits this fix is only for imx28, so there are some changes. > Greg, can this patchset is in -stable? Ok, but please put this information in the patches otherwise I'll forget why these are allowed in the -stable tree. thanks, greg k-h -- 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
