From: Wolfram Sang <wsa@the-dreams.de>
To: Lee Jones <lee.jones@linaro.org>
Cc: alokc@codeaurora.org, agross@kernel.org, robh+dt@kernel.org,
mark.rutland@arm.com, bjorn.andersson@linaro.org,
vkoul@kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org,
linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org
Subject: Re: [RESEND v3 1/1] i2c: qcom-geni: Provide an option to disable DMA processing
Date: Thu, 5 Sep 2019 20:20:59 +0200 [thread overview]
Message-ID: <20190905182058.GA5281@kunai> (raw)
In-Reply-To: <20190905144122.5689-1-lee.jones@linaro.org>
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On Thu, Sep 05, 2019 at 03:41:22PM +0100, Lee Jones wrote:
> We have a production-level laptop (Lenovo Yoga C630) which is exhibiting
> a rather horrific bug. When I2C HID devices are being scanned for at
> boot-time the QCom Geni based I2C (Serial Engine) attempts to use DMA.
> When it does, the laptop reboots and the user never sees the OS.
$subject is still wrong. And a paragraph that you are/were debugging the
root cause but to no avail so DMA gets disabled for now would be good for a
hotfix this late in the cycle.
>
> Signed-off-by: Lee Jones <lee.jones@linaro.org>
> ---
> drivers/i2c/busses/i2c-qcom-geni.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
> index a89bfce5388e..17abf60c94ae 100644
> --- a/drivers/i2c/busses/i2c-qcom-geni.c
> +++ b/drivers/i2c/busses/i2c-qcom-geni.c
> @@ -355,11 +355,13 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
> {
> dma_addr_t rx_dma;
> unsigned long time_left;
> - void *dma_buf;
> + void *dma_buf = NULL;
> struct geni_se *se = &gi2c->se;
> size_t len = msg->len;
>
> - dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
> + if (!of_machine_is_compatible("lenovo,yoga-c630"))
> + dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
> +
> if (dma_buf)
> geni_se_select_mode(se, GENI_SE_DMA);
> else
> @@ -394,11 +396,13 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
> {
> dma_addr_t tx_dma;
> unsigned long time_left;
> - void *dma_buf;
> + void *dma_buf = NULL;
> struct geni_se *se = &gi2c->se;
> size_t len = msg->len;
>
> - dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
> + if (!of_machine_is_compatible("lenovo,yoga-c630"))
> + dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
> +
> if (dma_buf)
> geni_se_select_mode(se, GENI_SE_DMA);
> else
> --
> 2.17.1
>
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WARNING: multiple messages have this Message-ID (diff)
From: Wolfram Sang <wsa@the-dreams.de>
To: Lee Jones <lee.jones@linaro.org>
Cc: mark.rutland@arm.com, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, agross@kernel.org,
robh+dt@kernel.org, bjorn.andersson@linaro.org, vkoul@kernel.org,
alokc@codeaurora.org, linux-i2c@vger.kernel.org,
linux-arm-msm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RESEND v3 1/1] i2c: qcom-geni: Provide an option to disable DMA processing
Date: Thu, 5 Sep 2019 20:20:59 +0200 [thread overview]
Message-ID: <20190905182058.GA5281@kunai> (raw)
In-Reply-To: <20190905144122.5689-1-lee.jones@linaro.org>
[-- Attachment #1.1: Type: text/plain, Size: 1983 bytes --]
On Thu, Sep 05, 2019 at 03:41:22PM +0100, Lee Jones wrote:
> We have a production-level laptop (Lenovo Yoga C630) which is exhibiting
> a rather horrific bug. When I2C HID devices are being scanned for at
> boot-time the QCom Geni based I2C (Serial Engine) attempts to use DMA.
> When it does, the laptop reboots and the user never sees the OS.
$subject is still wrong. And a paragraph that you are/were debugging the
root cause but to no avail so DMA gets disabled for now would be good for a
hotfix this late in the cycle.
>
> Signed-off-by: Lee Jones <lee.jones@linaro.org>
> ---
> drivers/i2c/busses/i2c-qcom-geni.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
> index a89bfce5388e..17abf60c94ae 100644
> --- a/drivers/i2c/busses/i2c-qcom-geni.c
> +++ b/drivers/i2c/busses/i2c-qcom-geni.c
> @@ -355,11 +355,13 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
> {
> dma_addr_t rx_dma;
> unsigned long time_left;
> - void *dma_buf;
> + void *dma_buf = NULL;
> struct geni_se *se = &gi2c->se;
> size_t len = msg->len;
>
> - dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
> + if (!of_machine_is_compatible("lenovo,yoga-c630"))
> + dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
> +
> if (dma_buf)
> geni_se_select_mode(se, GENI_SE_DMA);
> else
> @@ -394,11 +396,13 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
> {
> dma_addr_t tx_dma;
> unsigned long time_left;
> - void *dma_buf;
> + void *dma_buf = NULL;
> struct geni_se *se = &gi2c->se;
> size_t len = msg->len;
>
> - dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
> + if (!of_machine_is_compatible("lenovo,yoga-c630"))
> + dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
> +
> if (dma_buf)
> geni_se_select_mode(se, GENI_SE_DMA);
> else
> --
> 2.17.1
>
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next prev parent reply other threads:[~2019-09-05 18:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-05 14:41 [RESEND v3 1/1] i2c: qcom-geni: Provide an option to disable DMA processing Lee Jones
2019-09-05 14:41 ` Lee Jones
2019-09-05 18:20 ` Wolfram Sang [this message]
2019-09-05 18:20 ` Wolfram Sang
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