On Fri, May 22, 2020 at 11:48 AM Jassi Brar <jassisinghbrar@xxxxxxxxx> wrote: > > On Thu, May 21, 2020 at 7:24 AM Baolin Wang <baolin.wang7@xxxxxxxxx> wrote: > > > > Hi Jassi, > > > > On Wed, May 13, 2020 at 2:32 PM Baolin Wang <baolin.wang7@xxxxxxxxx> wrote: > > > > > > On Wed, May 13, 2020 at 2:05 PM Jassi Brar <jassisinghbrar@xxxxxxxxx> wrote: > > > > > > > > On Tue, May 12, 2020 at 11:14 PM Baolin Wang <baolin.wang7@xxxxxxxxx> wrote: > > > > > > > > > > Hi Jassi, > > > > > > > > > > On Thu, May 7, 2020 at 11:23 AM Baolin Wang <baolin.wang7@xxxxxxxxx> wrote: > > > > > > > > > > > > Hi Jassi, > > > > > > > > > > > > On Thu, May 7, 2020 at 7:25 AM Jassi Brar <jassisinghbrar@xxxxxxxxx> wrote: > > > > > > > > > > > > > > On Wed, May 6, 2020 at 8:29 AM Baolin Wang <baolin.wang7@xxxxxxxxx> wrote: > > > > > > > > > > > > > > > > Hi Jassi, > > > > > > > > > > > > > > > > On Tue, Apr 28, 2020 at 11:10 AM Baolin Wang <baolin.wang7@xxxxxxxxx> wrote: > > > > > > > > > > > > > > > > > > From: Baolin Wang <baolin.wang@xxxxxxxxxx> > > > > > > > > > > > > > > > > > > The Spreadtrum mailbox controller supports 8 channels to communicate > > > > > > > > > with MCUs, and it contains 2 different parts: inbox and outbox, which > > > > > > > > > are used to send and receive messages by IRQ mode. > > > > > > > > > > > > > > > > > > Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx> > > > > > > > > > Signed-off-by: Baolin Wang <baolin.wang7@xxxxxxxxx> > > > > > > > > > --- > > > > > > > > > Changes from v3: > > > > > > > > > - Save the id in mbox_chan.con_priv and remove the 'sprd_mbox_chan' > > > > > > > > > > > > > > > > > > Changes from v2: > > > > > > > > > - None. > > > > > > > > > > > > > > > > > > Changes from v1: > > > > > > > > > - None > > > > > > > > > > > > > > > > Gentle ping, do you have any other comments? Thanks. > > > > > > > > > > > > > > > Yea, I am still not sure about the error returned in send_data(). It > > > > > > > will either never hit or there will be no easy recovery from it. The > > > > > > > api expects the driver to tell it the last-tx was done only when it > > > > > > > can send the next message. (There may be case like sending depend on > > > > > > > remote, which can't be ensured before hand). > > > > > > > > > > > > Actually this is an unusual case, suppose the remote target did not > > > > > > fetch the message as soon as possile, which will cause the FIFO > > > > > > overflow, so in this case we can not send messages to the remote > > > > > > target any more, otherwise messages will be lost. Thus we can return > > > > > > errors to users to indicate that something wrong with the remote > > > > > > target need to be checked. > > > > > > > > > > > > So this validation in send_data() is mostly for debugging for this > > > > > > abnormal case and we will not trigger this issue if the remote target > > > > > > works well. So I think it is useful to keep this validation in > > > > > > send_data(). Thanks. > > > > > > > > > > Any comments? Thanks. > > > > > > > > > Same as my last post. > > > > > > I think I've explained the reason why we need add this validation in > > > my previous email, I am not sure how do you think? You still want to > > > remove this validation? > > > > Gentle ping. > > > > As I explained in previous email, this validation is for an unusual > > case, suppose the remote target did not fetch the message as soon as > > possile, which will cause the FIFO overflow, so in this case we can > > not send messages to the remote > > target any more, otherwise messages will be lost. Thus we can return > > errors to users to indicate that something wrong with the remote > > target need to be checked. > > > > So this validation in send_data() is mostly for debugging for this > > abnormal case and we will not trigger this issue if the remote target > > works well. So I think it is useful to keep this validation in > > send_data(). What do you think? Thanks. > > > I still think the same as before. > You should do this check before you call mbox_chan_txdone() and wait > if busy ... which is exactly the purpose of txdone(). > It seems harmless to be paranoid and place a block of code in > practically "if 0", but that sets bad precedence for other drivers. So > please move the check before txdone(). OK. I realized I can implement the flush() to make sure the transmission has been completed. Thanks. -- Baolin Wang
