Felipe Balbi <balbi@xxxxxx> writes:
> HI,
>
> On Tue, Mar 26, 2013 at 09:24:30PM +0100, Michael Grzeschik wrote:
>> On Tue, Mar 26, 2013 at 07:55:46PM +0200, Felipe Balbi wrote:
>> > Hi,
>> >
>> > On Tue, Mar 26, 2013 at 05:58:45PM +0100, Michael Grzeschik wrote:
>> > > A static count of transfer descriptors was used everywhere in the driver
>> > > with the fixed number 5. This patch adds a define, named TD_PAGE_COUNT,
>> > > and replaces all users of this value. This way its possible to have only
>> > > one parameter to change and limit the amount of buffer pointers per TD.
>> > >
>> > > Signed-off-by: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx>
>> > > ---
>> > > Changes since v1:
>> > > - renamed TD_COUNT to more precise TD_PAGE_COUNT
>> > > - changed TD_PAGE_COUNT to 5 based on the previous patch
>> > > - fixed patch description to address the tds buffers not the td itself
>> > >
>> > > drivers/usb/chipidea/ci.h | 1 +
>> > > drivers/usb/chipidea/udc.c | 6 +++---
>> > > 2 files changed, 4 insertions(+), 3 deletions(-)
>> > >
>> > > diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h
>> > > index 7dcd390..4ca3373 100644
>> > > --- a/drivers/usb/chipidea/ci.h
>> > > +++ b/drivers/usb/chipidea/ci.h
>> > > @@ -21,6 +21,7 @@
>> > > /******************************************************************************
>> > > * DEFINE
>> > > *****************************************************************************/
>> > > +#define TD_PAGE_COUNT 5
>> > > #define CI13XXX_PAGE_SIZE 4096ul /* page size for TD's */
>> > > #define ENDPT_MAX 32
>> > > #define RX 0 /* similar to USB_DIR_OUT but can be used as an index */
>> > > diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
>> > > index e779870..4294c2c 100644
>> > > --- a/drivers/usb/chipidea/udc.c
>> > > +++ b/drivers/usb/chipidea/udc.c
>> > > @@ -445,7 +445,7 @@ _hardware_enqueue(struct ci13xxx_ep *mEp, struct ci13xxx_req *mReq,
>> > > mReq->ptr->token |= TD_IOC;
>> > > }
>> > > mReq->ptr->page[0] = mReq->req.dma;
>> > > - for (i = 1; i < 5; i++)
>> > > + for (i = 1; i < TD_PAGE_COUNT; i++)
>> > > mReq->ptr->page[i] =
>> > > (mReq->req.dma + i * CI13XXX_PAGE_SIZE) & ~TD_RESERVED_MASK;
>> > >
>> > > @@ -697,8 +697,8 @@ static int _ep_queue(struct usb_ep *ep, struct usb_request *req,
>> > > goto done;
>> > > }
>> > >
>> > > - if (req->length > 4 * CI13XXX_PAGE_SIZE) {
>> > > - req->length = 4 * CI13XXX_PAGE_SIZE;
>> > > + if (req->length > (TD_PAGE_COUNT - 1) * CI13XXX_PAGE_SIZE) {
>> > > + req->length = (TD_PAGE_COUNT - 1) * CI13XXX_PAGE_SIZE;
>> >
>> > this is a bug. You shouldn't change req->length, you might completely
>> > screw up a gadget driver. Don't change anything what the gadget driver
>> > passes to you, ever. Change some private structure instead.
>> >
>> > (yeah, I know it's not part of $subject)
>>
>> Beside that bug get fixed by the patch
>> "usb: chipidea: udc: add multiple td support to hardware_{en,de}queue"
>> in that series.
>
> *ALL BUG FIXES DESERVE THEIR OWN PATCH*. Burn this into non-volatile
> memory.
>
> When writing patches, whenever you find a bug fix, you create a separate
> branch on top of newest -rc (or Greg's usb-linus or my 'fixes' branch
> depending on which driver you're fixing) fix the bug with as few lines
> as possible and send the patch so it can be applied during the -rc,
> without creating dependencies with patches going for next merge window.
>
> If bug was introduced prior to last merge window (e.g. you figure bug
> was introduced in v3.6, instead of v3.8) then you add Cc
> stable@xxxxxxxxxxxxxxx to make sure folks using older kernels also have
> the fix.
>
> I would suggest Alex doesn't take this series until it's properly split
> into a bugfixes series and another series of cleanups/new features for
> next.
I hear ya
Regards,
--
Alex
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