From: Vinod Koul <vkoul@kernel.org>
To: Ansuel Smith <ansuelsmth@gmail.com>
Cc: Andy Gross <agross@kernel.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Kishon Vijay Abraham I <kishon@ti.com>,
linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] drivers: phy: qcom: ipq806x-usb: conver latch function to pool macro
Date: Mon, 24 Jan 2022 09:57:38 +0530 [thread overview]
Message-ID: <Ye4qujlrcfxPTy2j@matsya> (raw)
In-Reply-To: <61ed6a44.1c69fb81.35728.5e8b@mx.google.com>
On 23-01-22, 15:46, Ansuel Smith wrote:
> On Sun, Jan 23, 2022 at 05:22:18PM +0530, Vinod Koul wrote:
> > On 17-01-22, 01:26, Ansuel Smith wrote:
> > > Convert latch function to readl pool macro to tidy things up.
> > >
> > > Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
> > > ---
> > > drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c | 17 +++++------------
> > > 1 file changed, 5 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c b/drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c
> > > index 6788e0e8272a..ab2d1431546d 100644
> > > --- a/drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c
> > > +++ b/drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c
> > > @@ -112,6 +112,9 @@
> > > #define SS_CR_READ_REG BIT(0)
> > > #define SS_CR_WRITE_REG BIT(0)
> > >
> > > +#define LATCH_SLEEP 40
> > > +#define LATCH_TIMEOUT 100
> > > +
> > > struct usb_phy {
> > > void __iomem *base;
> > > struct device *dev;
> > > @@ -156,19 +159,9 @@ static inline void usb_phy_write_readback(struct usb_phy *phy_dwc3,
> > >
> > > static int wait_for_latch(void __iomem *addr)
> > > {
> > > - u32 retry = 10;
> > > -
> > > - while (true) {
> > > - if (!readl(addr))
> > > - break;
> >
> > we break if read returns non zero value...
> >
> > Do you know what is the value expected?
> >
>
> If I understand the logic here, we write a value and we wait for it to
> get applied. To confirm that we execute a writel and then we readl the
> same address until it does return a value. That is the way used to
> understand that the write process has finished and that the value has
> been applied/we can write again.
>
> > > -
> > > - if (--retry == 0)
> > > - return -ETIMEDOUT;
> > > -
> > > - usleep_range(10, 20);
> > > - }
> > > + u32 val;
> >
> > Okay this contains garbage..
>
> I think I didn't understand, val value will get replaced by readl in
> the pool_timeout function.
>
> > >
> > > - return 0;
> > > + return readl_poll_timeout(addr, val, !val, LATCH_SLEEP, LATCH_TIMEOUT);
> >
> > and we are waiting for it read a garbage value!
> >
>
> Again could be very confused and wrong but the pool_timeout macro does
> the exact same thing of the wait_for_latch function with th only
> difference of handling the sleep differently. We put in val the return
> of readl and the break condition as !val. Or I didn't understand the
> concern about garbage value.
Sorry I read the readl_poll_timeout wrongly, this seems correct, I will
pick these now.
--
~Vinod
WARNING: multiple messages have this Message-ID (diff)
From: Vinod Koul <vkoul@kernel.org>
To: Ansuel Smith <ansuelsmth@gmail.com>
Cc: Andy Gross <agross@kernel.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Kishon Vijay Abraham I <kishon@ti.com>,
linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] drivers: phy: qcom: ipq806x-usb: conver latch function to pool macro
Date: Mon, 24 Jan 2022 09:57:38 +0530 [thread overview]
Message-ID: <Ye4qujlrcfxPTy2j@matsya> (raw)
In-Reply-To: <61ed6a44.1c69fb81.35728.5e8b@mx.google.com>
On 23-01-22, 15:46, Ansuel Smith wrote:
> On Sun, Jan 23, 2022 at 05:22:18PM +0530, Vinod Koul wrote:
> > On 17-01-22, 01:26, Ansuel Smith wrote:
> > > Convert latch function to readl pool macro to tidy things up.
> > >
> > > Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
> > > ---
> > > drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c | 17 +++++------------
> > > 1 file changed, 5 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c b/drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c
> > > index 6788e0e8272a..ab2d1431546d 100644
> > > --- a/drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c
> > > +++ b/drivers/phy/qualcomm/phy-qcom-ipq806x-usb.c
> > > @@ -112,6 +112,9 @@
> > > #define SS_CR_READ_REG BIT(0)
> > > #define SS_CR_WRITE_REG BIT(0)
> > >
> > > +#define LATCH_SLEEP 40
> > > +#define LATCH_TIMEOUT 100
> > > +
> > > struct usb_phy {
> > > void __iomem *base;
> > > struct device *dev;
> > > @@ -156,19 +159,9 @@ static inline void usb_phy_write_readback(struct usb_phy *phy_dwc3,
> > >
> > > static int wait_for_latch(void __iomem *addr)
> > > {
> > > - u32 retry = 10;
> > > -
> > > - while (true) {
> > > - if (!readl(addr))
> > > - break;
> >
> > we break if read returns non zero value...
> >
> > Do you know what is the value expected?
> >
>
> If I understand the logic here, we write a value and we wait for it to
> get applied. To confirm that we execute a writel and then we readl the
> same address until it does return a value. That is the way used to
> understand that the write process has finished and that the value has
> been applied/we can write again.
>
> > > -
> > > - if (--retry == 0)
> > > - return -ETIMEDOUT;
> > > -
> > > - usleep_range(10, 20);
> > > - }
> > > + u32 val;
> >
> > Okay this contains garbage..
>
> I think I didn't understand, val value will get replaced by readl in
> the pool_timeout function.
>
> > >
> > > - return 0;
> > > + return readl_poll_timeout(addr, val, !val, LATCH_SLEEP, LATCH_TIMEOUT);
> >
> > and we are waiting for it read a garbage value!
> >
>
> Again could be very confused and wrong but the pool_timeout macro does
> the exact same thing of the wait_for_latch function with th only
> difference of handling the sleep differently. We put in val the return
> of readl and the break condition as !val. Or I didn't understand the
> concern about garbage value.
Sorry I read the readl_poll_timeout wrongly, this seems correct, I will
pick these now.
--
~Vinod
--
linux-phy mailing list
linux-phy@lists.infradead.org
https://lists.infradead.org/mailman/listinfo/linux-phy
next prev parent reply other threads:[~2022-01-24 4:27 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-17 0:26 [PATCH 1/2] drivers: phy: qcom: ipq806x-usb: convert to BITFIELD macro Ansuel Smith
2022-01-17 0:26 ` Ansuel Smith
2022-01-17 0:26 ` [PATCH 2/2] drivers: phy: qcom: ipq806x-usb: conver latch function to pool macro Ansuel Smith
2022-01-17 0:26 ` Ansuel Smith
2022-01-23 11:52 ` Vinod Koul
2022-01-23 11:52 ` Vinod Koul
2022-01-23 14:46 ` Ansuel Smith
2022-01-23 14:46 ` Ansuel Smith
2022-01-24 4:27 ` Vinod Koul [this message]
2022-01-24 4:27 ` Vinod Koul
2022-01-24 4:28 ` [PATCH 1/2] drivers: phy: qcom: ipq806x-usb: convert to BITFIELD macro Vinod Koul
2022-01-24 4:28 ` Vinod Koul
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