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? -- Best Regards, Peter Chen -- 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
