On Wed, 24 Sep 2014, Johan Hovold wrote: > On Wed, Sep 24, 2014 at 11:12:06AM +0100, Lee Jones wrote: > > On Mon, 22 Sep 2014, Octavian Purdila wrote: > > > > > Currently the I/O buffer is allocated part of the device status > > > structure, potentially sharing the same cache line with other members > > > in this structure. > > > > > > Allocate the buffer separately, to avoid the I/O operations corrupting > > > the device status structure due to cache line sharing. > > > > > > Compiled tested only as I don't have access to hardware. > > > > > > Signed-off-by: Octavian Purdila <octavian.purd...@intel.com> > > > --- > > > drivers/mfd/viperboard.c | 8 ++++++++ > > > include/linux/mfd/viperboard.h | 2 +- > > > 2 files changed, 9 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/mfd/viperboard.c b/drivers/mfd/viperboard.c > > > index e00f534..5f62f4e 100644 > > > --- a/drivers/mfd/viperboard.c > > > +++ b/drivers/mfd/viperboard.c > > > @@ -64,6 +64,12 @@ static int vprbrd_probe(struct usb_interface > > > *interface, > > > return -ENOMEM; > > > } > > > > > > + vb->buf = kzalloc(sizeof(struct vprbrd_i2c_write_msg), GFP_KERNEL); > > > > Can you obtain the 'struct device' first then use managed resources > > (devm_*)? > > I think any devres conversion should be done in a follow-up patch and > not be included in the fix (e.g. in order to facilitate backporting). We > also don't want to mix allocation schemes.
I agree, but equally I'm not keen on accepting this patch as I believe it could be done better. Please submit two patches, one converting to shared resources and this being the subsequent one, fixed up to do the right thing. -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
