On Wed, Jul 15, 2015 at 6:30 AM, Moritz Fischer <moritz.fischer@xxxxxxxxx> wrote: > + > +static void xilinx_mbox_rx_data(struct mbox_chan *chan) > +{ > + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); > + u32 data; > + > + if (xilinx_mbox_pending(mbox)) { > + data = readl_relaxed(mbox->mbox_base + MAILBOX_REG_RDDATA); > + mbox_chan_received_data(chan, (void *)data); > If RDDATA is a FIFO, then above seems wrong - you are assuming messages are always going to be exactly 32-bits for every protocol. Ideally you should empty the fifo fully, at least when RX has an interrupt. > + > +static int xilinx_mbox_irq_send_data(struct mbox_chan *chan, void *data) > +{ > + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); > + u32 *udata = data; > + > + if (xilinx_mbox_full(mbox)) > + return -EBUSY; > This check is redundant. last_tx_done already makes sure this is always true. > + /* enable interrupt before send */ > + xilinx_mbox_tx_intmask(mbox, true); > + > + writel_relaxed(*udata, mbox->mbox_base + MAILBOX_REG_WRDATA); > + >From status EMPTY and FULL, it seems WRDATA is a FIFO. So here also you should expect messages to be <= fifo depth. And not assume exactly 32bit messages always. > + > +static bool xilinx_mbox_last_tx_done(struct mbox_chan *chan) > +{ > + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); > + > + /* return false if mailbox is full */ > + return !xilinx_mbox_full(mbox); > Instead of FULL, I think it should check for stricter EMPTY status ... mbox api submits only 1 message at a time. > + > +static bool xilinx_mbox_peek_data(struct mbox_chan *chan) > +{ > + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); > + > + return xilinx_mbox_pending(mbox); > +} > + > +static void xilinx_mbox_irq_shutdown(struct mbox_chan *chan) > +{ > + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); > + > + /* mask all interrupts */ > + writel_relaxed(0, mbox->mbox_base + MAILBOX_REG_IE); > + > + clk_disable_unprepare(mbox->clk); > + > + free_irq(mbox->irq, chan); > +} > + > +static void xilinx_mbox_poll_shutdown(struct mbox_chan *chan) > +{ > + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); > + > + del_timer_sync(&mbox->rxpoll_timer); > + > + clk_disable_unprepare(mbox->clk); > +} > + > +static const struct mbox_chan_ops xilinx_mbox_irq_ops = { > + .send_data = xilinx_mbox_irq_send_data, > + .startup = xilinx_mbox_irq_startup, > + .shutdown = xilinx_mbox_irq_shutdown, > + .last_tx_done = xilinx_mbox_last_tx_done, > + .peek_data = xilinx_mbox_peek_data, > +}; > + > +static const struct mbox_chan_ops xilinx_mbox_poll_ops = { > + .send_data = xilinx_mbox_poll_send_data, > + .startup = xilinx_mbox_poll_startup, > + .shutdown = xilinx_mbox_poll_shutdown, > + .last_tx_done = xilinx_mbox_last_tx_done, > + .peek_data = xilinx_mbox_peek_data, > +}; > + > +static int xilinx_mbox_probe(struct platform_device *pdev) > +{ > + struct xilinx_mbox *mbox; > + struct resource *regs; > + int ret; > + > + mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL); > + if (!mbox) > + return -ENOMEM; > + > + /* get clk and enable */ > + mbox->clk = devm_clk_get(&pdev->dev, "mbox"); > + if (IS_ERR(mbox->clk)) { > + dev_err(&pdev->dev, "Couldn't get clk.\n"); > + return PTR_ERR(mbox->clk); > + } > + > + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + > + mbox->mbox_base = devm_ioremap_resource(&pdev->dev, regs); > + if (IS_ERR(mbox->mbox_base)) > + return PTR_ERR(mbox->mbox_base); > + > + mbox->irq = platform_get_irq(pdev, 0); > + /* if irq is present, we can use it, otherwise, poll */ > + if (mbox->irq > 0) { > + mbox->controller.txdone_irq = true; > + mbox->controller.ops = &xilinx_mbox_irq_ops; > + } else { > + dev_info(&pdev->dev, "IRQ not found, fallback to polling.\n"); > + mbox->controller.txdone_poll = true; > + mbox->controller.txpoll_period = MBOX_POLLING_MS; > + mbox->controller.ops = &xilinx_mbox_poll_ops; > + > + setup_timer(&mbox->rxpoll_timer, xilinx_mbox_poll_rx, > + (unsigned long)&mbox->chan); > I believe there is indeed some platform that doesn't have RX-Interrupt? If no, please remove this. If yes, you may want to get some hint from platform about the size of messages and do mbox_chan_received_data() only upon reading those many bytes. Cheers. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html