Hi Tzung-Bi, Thanks for your suggestions. On Wed, 2021-11-24 at 18:25 +0800, Tzung-Bi Shih wrote: > > On Wed, Nov 24, 2021 at 04:45:13PM +0800, allen-kh.cheng wrote: > > > > diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig > > > > index c9fc06c7e685..fc99d9fc80af 100644 > > > > --- a/drivers/mailbox/Kconfig > > > > +++ b/drivers/mailbox/Kconfig > > > > @@ -236,6 +236,13 @@ config MTK_CMDQ_MBOX > > > > critical time limitation, such as updating display > > > > configuration > > > > during the vblank. > > > > > > > > +config MTK_ADSP_IPC_MBOX > > > > + tristate "MediaTek ADSP Mailbox Controller" > > > > + depends on ARCH_MEDIATEK || COMPILE_TEST > > > > + help > > > > + Say yes here to add support for MediaTek ADSP IPC mailbox > > > > controller > > > > + driver. It is used to send short messages between > > processors > > > > with dsp. > > > > > Although the file didn't maintain alphabetical order, to be neat, > > moving MTK_ADSP_IPC_MBOX before MTK_CMDQ_MBOX makes more sense. > > > > > > diff --git a/drivers/mailbox/Makefile > > b/drivers/mailbox/Makefile > > > > index c2089f04887e..479a9ae56d5e 100644 > > > > --- a/drivers/mailbox/Makefile > > > > +++ b/drivers/mailbox/Makefile > > > > @@ -51,6 +51,8 @@ obj-$(CONFIG_STM32_IPCC) += stm32-ipcc.o > > > > > > > > obj-$(CONFIG_MTK_CMDQ_MBOX) += mtk-cmdq-mailbox.o > > > > > > > > +obj-$(CONFIG_MTK_ADSP_IPC_MBOX) += mtk-adsp-mailbox.o > > > > + > > > > > Ditto. Move CONFIG_MTK_ADSP_IPC_MBOX before CONFIG_MTK_CMDQ_MBOX > > without blank line separation. > > > > > > diff --git a/drivers/mailbox/mtk-adsp-mailbox.c > > > > b/drivers/mailbox/mtk-adsp-mailbox.c > > > > > [...] > > > > +static irqreturn_t mtk_adsp_ipc_irq_handler(int irq, void > > *data) > > > > +{ > > > > + struct mbox_chan *ch = (struct mbox_chan *)data; > > > > > The cast should be able to remove. > > > > > > +static irqreturn_t mtk_adsp_ipc_handler(int irq, void *data) > > > > +{ > > > > + struct mbox_chan *ch = (struct mbox_chan *)data; > > > > > The cast should be able to remove. > > > > > > +static int mtk_adsp_mbox_startup(struct mbox_chan *chan) > > > > +{ > > > > + struct adsp_mbox_ch_info *ch_info = chan->con_priv; > > > > + void __iomem *reg = ch_info->va_reg; > > > > + > > > > + /* Clear DSP mbox command */ > > > > + writel(0xFFFFFFFF, reg + MTK_ADSP_MBOX_IN_CMD_CLR); > > > > + writel(0xFFFFFFFF, reg + MTK_ADSP_MBOX_OUT_CMD_CLR); > > > > + > > > > + return 0; > > > > +} > > > > + > > > > +static void mtk_adsp_mbox_shutdown(struct mbox_chan *chan) > > > > +{ > > > > + chan->con_priv = NULL; > > > > +} > > > > > Shall mtk_adsp_mbox_shutdown() also clear DSP mbox? I.e.: > > writel(0xFFFFFFFF, reg + MTK_ADSP_MBOX_IN_CMD_CLR); > > writel(0xFFFFFFFF, reg + MTK_ADSP_MBOX_OUT_CMD_CLR); > > > > > > +static int mtk_adsp_mbox_send_data(struct mbox_chan *chan, > > void > > > > *data) > > > > +{ > > > > + struct adsp_mbox_ch_info *ch_info = chan->con_priv; > > > > + void __iomem *reg = ch_info->va_reg; > > > > + > > > > + spin_lock(&ch_info->lock); > > > > + writel(ch_info->ipc_op_val, reg + MTK_ADSP_MBOX_IN_CMD); > > > > + spin_unlock(&ch_info->lock); > > > > > Why does it need the lock? > > > > Is the write to MTK_ADSP_MBOX_IN_CMD a synchronous operation? > > - If yes, I failed to understand why does it need the lock. Every > > calls to mtk_adsp_mbox_send_data() should wait for the data > transfer > > completion. > > - If no, I also failed to understand > why. mtk_adsp_mbox_send_data() > > has no way to be aware of the transfer completion. Would expect a > > loop for checking the completion for the case. > > > In ADSP MBOX IPC flow, Host would call mbox send data when the shared data transfer completed. (mtk_adsp_mbox_send_data will notice client using MTK_ADSP_MBOX_IN_CMD) It’s more like a signal. In general case, There may be some hosts use the same mbox channel. I think it’s better using lock to protect access to MTK_ADSP_MBOX_IN_CMD registers Thanks, Allen > > > > +static bool mtk_adsp_mbox_last_tx_done(struct mbox_chan *chan) > > > > +{ > > > > + struct adsp_mbox_ch_info *ch_info = chan->con_priv; > > > > + void __iomem *reg = ch_info->va_reg; > > > > + u32 op = readl(reg + MTK_ADSP_MBOX_IN_CMD); > > > > + > > > > + return (op == 0) ? true : false; > > > > > To be concise, return readl(...) == 0; > > > > > > +static int mtk_adsp_mbox_probe(struct platform_device *pdev) > > > > +{ > > > > > [...] > > > > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > > > + if (!res) { > > > > + dev_err(dev, "no adsp mbox register resource\n"); > > > > + return -ENXIO; > > > > + } > > > > + > > > > + size = resource_size(res); > > > > + priv->va_mboxreg = devm_ioremap(dev, (phys_addr_t)res- > > >start, > > > > size); > > > > + if (IS_ERR(priv->va_mboxreg)) > > > > + return PTR_ERR(priv->va_mboxreg); > > > > > Use devm_platform_ioremap_resource(), it should be equivalent. > > > > > > + /* set adsp mbox channel info */ > > > > + ch_info = devm_kzalloc(mbox->dev, sizeof(*ch_info), > > > > GFP_KERNEL); > > > > > To be neat, use dev instead of mbox->dev. > > > > > > + ret = devm_mbox_controller_register(dev, &priv->mbox); > > > > + if (ret < 0) > > > > + dev_err(dev, "error: failed to register mailbox:%d\n", > > > > ret); > > > > + > > > > + return ret; > > > > > To be concise, return devm_mbox_controller_register(...); > > >