Messages in this thread Patch in this message | | | Subject | Re: [PATCH v2] mailbox: Hi3660: Fixup mailbox state machine malfunction issue | From | Valentin Schneider <> | Date | Mon, 10 Dec 2018 18:31:47 +0000 |
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Hi,
On 03/12/2018 06:13, Kevin Wangtao wrote: > Current mailbox driver of Hi3660 release the mailbox directly > before sending a new message which may cause last message lost > and next message sending doesn't take effect actually. > > This patch fixes this issue by following the right process below, > each time before sending a message, mailbox driver will check > whether the mailbox is in ready state, if last message has been > acknowledged, mailbox driver will clear the ack state to turn > the mailbox to ready state again. > > Signed-off-by: Kevin Wangtao <kevin.wangtao@hisilicon.com>
Validated using sysbench at each OPP ([1]). Test passes with patch and fails without:
| CPU | OPP | Base | Patch | |------+---------+------+-------| | CPU0 | 533000 | 104 | 104 | | CPU0 | 999000 | 104 | 201 | | CPU0 | 140200 | 285 | 285 | | CPU0 | 1709000 | 285 | 349 | | CPU0 | 1844000 | 377 | 377 | |------+---------+------+-------| | CPU4 | 903000 | 249 | 248 | | CPU4 | 1421000 | 249 | 394 | | CPU4 | 1805000 | 500 | 500 | | CPU4 | 2112000 | 499 | 583 | | CPU4 | 2362000 | 653 | 654 |
We need this pretty badly, otherwise frequency setting is a coin toss.
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Thanks, Valentin
[1]: https://github.com/ARM-software/lisa/blob/next/lisa/tests/kernel/cpufreq/sanity.py#L23
Ran the above with this script on each kernel:
----->8----- #!/usr/bin/env python3
from lisa.env import TestEnv from lisa.tests.kernel.cpufreq.sanity import UserspaceSanity
te = TestEnv.from_cli()
print(UserspaceSanity.from_testenv(te).test_performance_sanity()) -----8<-----
> --- > Changes v1 -> v2: > - update commit message > > drivers/mailbox/hi3660-mailbox.c | 22 ++++++++++------------ > 1 file changed, 10 insertions(+), 12 deletions(-) > > diff --git a/drivers/mailbox/hi3660-mailbox.c b/drivers/mailbox/hi3660-mailbox.c > index 3eea6b6..035b71a 100644 > --- a/drivers/mailbox/hi3660-mailbox.c > +++ b/drivers/mailbox/hi3660-mailbox.c > @@ -38,6 +38,7 @@ > #define MBOX_AUTOMATIC_ACK 1 > > #define MBOX_STATE_IDLE BIT(4) > +#define MBOX_STATE_READY BIT(5) > #define MBOX_STATE_ACK BIT(7) > > #define MBOX_MSG_LEN 8 > @@ -91,8 +92,8 @@ static int hi3660_mbox_check_state(struct mbox_chan *chan) > unsigned long val; > unsigned int ret; > > - /* Mailbox is idle so directly bail out */ > - if (readl(base + MBOX_MODE_REG) & MBOX_STATE_IDLE) > + /* Mailbox is ready to use */ > + if (readl(base + MBOX_MODE_REG) & MBOX_STATE_READY) > return 0; > > /* Wait for acknowledge from remote */ > @@ -103,9 +104,9 @@ static int hi3660_mbox_check_state(struct mbox_chan *chan) > return ret; > } > > - /* Ensure channel is released */ > - writel(0xffffffff, base + MBOX_IMASK_REG); > - writel(BIT(mchan->ack_irq), base + MBOX_SRC_REG); > + /* clear ack state, mailbox will get back to ready state */ > + writel(BIT(mchan->ack_irq), base + MBOX_ICLR_REG); > + > return 0; > } > > @@ -160,10 +161,6 @@ static int hi3660_mbox_startup(struct mbox_chan *chan) > { > int ret; > > - ret = hi3660_mbox_check_state(chan); > - if (ret) > - return ret; > - > ret = hi3660_mbox_unlock(chan); > if (ret) > return ret; > @@ -183,10 +180,11 @@ static int hi3660_mbox_send_data(struct mbox_chan *chan, void *msg) > void __iomem *base = MBOX_BASE(mbox, ch); > u32 *buf = msg; > unsigned int i; > + int ret; > > - /* Ensure channel is released */ > - writel_relaxed(0xffffffff, base + MBOX_IMASK_REG); > - writel_relaxed(BIT(mchan->ack_irq), base + MBOX_SRC_REG); > + ret = hi3660_mbox_check_state(chan); > + if (ret) > + return ret; > > /* Clear mask for destination interrupt */ > writel_relaxed(~BIT(mchan->dst_irq), base + MBOX_IMASK_REG); >
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