From: Olof Johansson <olof@lixom.net>
To: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: khilman@linaro.org, arm@kernel.org, agross@codeaurora.org,
galak@codeaurora.org, linux-arm-kernel@lists.infradead.org,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] soc: qcom: do not disable the iface clock in probe
Date: Tue, 23 Sep 2014 21:39:05 -0700 [thread overview]
Message-ID: <20140924043905.GA24803@localhost> (raw)
In-Reply-To: <1411500054-13600-1-git-send-email-srinivas.kandagatla@linaro.org>
On Tue, Sep 23, 2014 at 08:20:54PM +0100, Srinivas Kandagatla wrote:
> since commit 31964ffebbb9 ("tty: serial: msm: Remove direct access to GSBI")'
> serial hangs if earlyprintk are enabled.
>
> This hang is noticed only when the GSBI driver is probed and all the
> earlyprintks before gsbi probe are seen on the console.
> The reason why it hangs is because GSBI driver disables hclk in its
> probe function without realizing that the serial IP might be in use by
> a bootconsole. As gsbi driver disables the clock in probe the
> bootconsole locks up.
>
> Turning off hclk's could be dangerous if there are system components
> like earlyprintk using the hclk.
>
> This patch fixes the issue by delegating the clock management to
> probe and remove functions in gsbi rather than disabling the clock in probe.
>
> More detailed problem description can be found here:
> http://www.spinics.net/lists/linux-arm-msm/msg10589.html
>
> Tested-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> ---
> Hi Kevin,
>
> Am resending this patch with reference to the problem and adding more
> details to the log.
>
> Could you pick this fix for the next rc, as this fixes a serial console
> hang with earlyprintk on SOCs like APQ8064.
>
> Changes since v1:
> - added more info in the change log as requested by Kumar and Kevin.
Applied to fixes.
-Olof
WARNING: multiple messages have this Message-ID (diff)
From: olof@lixom.net (Olof Johansson)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] soc: qcom: do not disable the iface clock in probe
Date: Tue, 23 Sep 2014 21:39:05 -0700 [thread overview]
Message-ID: <20140924043905.GA24803@localhost> (raw)
In-Reply-To: <1411500054-13600-1-git-send-email-srinivas.kandagatla@linaro.org>
On Tue, Sep 23, 2014 at 08:20:54PM +0100, Srinivas Kandagatla wrote:
> since commit 31964ffebbb9 ("tty: serial: msm: Remove direct access to GSBI")'
> serial hangs if earlyprintk are enabled.
>
> This hang is noticed only when the GSBI driver is probed and all the
> earlyprintks before gsbi probe are seen on the console.
> The reason why it hangs is because GSBI driver disables hclk in its
> probe function without realizing that the serial IP might be in use by
> a bootconsole. As gsbi driver disables the clock in probe the
> bootconsole locks up.
>
> Turning off hclk's could be dangerous if there are system components
> like earlyprintk using the hclk.
>
> This patch fixes the issue by delegating the clock management to
> probe and remove functions in gsbi rather than disabling the clock in probe.
>
> More detailed problem description can be found here:
> http://www.spinics.net/lists/linux-arm-msm/msg10589.html
>
> Tested-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> ---
> Hi Kevin,
>
> Am resending this patch with reference to the problem and adding more
> details to the log.
>
> Could you pick this fix for the next rc, as this fixes a serial console
> hang with earlyprintk on SOCs like APQ8064.
>
> Changes since v1:
> - added more info in the change log as requested by Kumar and Kevin.
Applied to fixes.
-Olof
next prev parent reply other threads:[~2014-09-24 5:38 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-23 19:20 [PATCH v2] soc: qcom: do not disable the iface clock in probe Srinivas Kandagatla
2014-09-23 19:20 ` Srinivas Kandagatla
2014-09-24 4:39 ` Olof Johansson [this message]
2014-09-24 4:39 ` Olof Johansson
2014-09-24 15:22 ` Kevin Hilman
2014-09-24 15:22 ` Kevin Hilman
2014-09-24 15:30 ` Srinivas Kandagatla
2014-09-24 15:30 ` Srinivas Kandagatla
2014-09-25 22:59 ` Kevin Hilman
2014-09-25 22:59 ` Kevin Hilman
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