Re: [PATCH 4/8] bus: mhi: Add inbound buffers allocation flag

Loic Poulain
2021-06-24T15:30:32Z

Hi Greg,

On Thu, 24 Jun 2021 at 15:51, Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Mon, Jun 21, 2021 at 09:46:12PM +0530, Manivannan Sadhasivam wrote:
> > From: Loic Poulain <loic.poulain@linaro.org>
> >
> > Currently, the MHI controller driver defines which channels should
> > have their inbound buffers allocated and queued. But ideally, this is
> > something that should be decided by the MHI device driver instead,
> > which actually deals with that buffers.
> >
> > Add a flag parameter to mhi_prepare_for_transfer allowing to specify
> > if buffers have to be allocated and queued by the MHI stack.
> >
> > Keep auto_queue flag for now, but should be removed at some point.
> >
> > Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
> > Tested-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
> > Reviewed-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
> > Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
> > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > Acked-by: Jakub Kicinski <kuba@kernel.org>
> > Link: https://lore.kernel.org/r/1621603519-16773-1-git-send-email-loic.poulain@linaro.org
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[...]
> > +/**
> > + * enum mhi_chan_flags - MHI channel flags
> > + * @MHI_CH_INBOUND_ALLOC_BUFS: Automatically allocate and queue inbound buffers
> > + */
> > +enum mhi_chan_flags {
> > + MHI_CH_INBOUND_ALLOC_BUFS = BIT(0),
>
> Why is an enumerated type a bitfield?
>
> Please just use integers for enumerated types.

This 'trick' for listing flags is used in other places like drm,
mac80211, etc...: grep -r "BIT(0)," ./include/

I don't understand why it would not be right? should we simply use
a list of defines for this?

Regards,
Loic