From: Jaehoon Chung <jh80.chung@samsung.com>
To: Olliver Schinagl <oliver@schinagl.nl>,
Ulf Hansson <ulf.hansson@linaro.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>,
Chen-Yu Tsai <wens@csie.org>,
Venu Byravarasu <vbyravarasu@nvidia.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Michal Hocko <mhocko@suse.com>,
Lars-Peter Clausen <lars@metafoo.de>,
Sudeep Holla <Sudeep.Holla@arm.com>,
Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>,
Wolfram Sang <wsa+renesas@sang-engineering.com>,
Wenkai Du <wenkai.du@intel.com>,
Chaotian Jing <chaotian.jing@mediatek.com>,
Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
Hans de Goede <hdegoede@redhat.com>,
Michal Suchanek <hramrach@gmail.com>,
linux-mmc <linux-mmc@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 1/2] mmc: core: Improve marking broken HPI through devicetree
Date: Tue, 19 Apr 2016 21:44:57 +0900 [thread overview]
Message-ID: <57162849.3070108@samsung.com> (raw)
In-Reply-To: <57162270.6040701@schinagl.nl>
Hi Olliver,
On 04/19/2016 09:20 PM, Olliver Schinagl wrote:
> Hey Jaehoon,
>
> On 19-04-16 11:49, Jaehoon Chung wrote:
>> Hi
>>
>> On 04/19/2016 06:42 PM, Olliver Schinagl wrote:
>>> Hi Ulf,
>>>
>>> On 19-04-16 11:29, Ulf Hansson wrote:
>>>> On 19 April 2016 at 09:12, Olliver Schinagl <oliver@schinagl.nl> wrote:
>>>>> In patch 81f8a7be66 Hans de Goede added a patch to allow marking an mmc
>>>>> device as to having an broken HPI implementation. After talking some
>>>>> with Hans, we now think it is actually the mmc controller that can be
>>>>> broken and not support broken HPI's.
>>>> I don't want us to invent a DT binding for something you *think* is a
>>>> HW controller issue.
>>>>
>>>> Have you really excluded that this isn't a software issue? Me
>>>> personally haven't been using HPI that much so I can't really tell
>>>> about the code robustness from the mmc core (mmc protocol point of
>>>> view).
>>> Well this patch goes hand in hand so to speak with the broken-hpi patch introduced by him, he did most of the investigation. We just discussed how to handle it and asked me to cook up the patch.
>> I didn't understand why add this property. Is this same patch?
>>
>> commit 81f8a7be6642b4c26ab681b2e0f4c4120a6de1b0
>> Author: Hans de Goede <hdegoede@redhat.com>
>> Date: Wed Apr 1 17:26:23 2015 +0200
>>
>> mmc: Add support for marking hpi as broken through devicetree
>>
>> The eMMC on a tablet I've will stop working / communicating as soon as
>> the kernel executes:
>>
>> mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
>> EXT_CSD_HPI_MGMT, 1,
>> card->ext_csd.generic_cmd6_time);
>>
>> There seems to be no way to reliable identify eMMC-s which have a broken
>> hpi implementation, but at least for eMMC's which are soldered onto a board
>> we can work around this by specifying that hpi is broken in devicetree.
> Similar, this does it on the card level, e.g. you mark a card as having a broken HPI implementation.
>
> The truth is, the card may not be broken at all, but the mmc controller so we add a property on the controller level.
>
> What Ulf is pondering, if this is not a software stack problem, rather then a hardware implementation, which I don't know.
Hmm..problem is mmc controller side..it's strange.
How did you know this problem is on mmc controller side?
Well, i should be also missing something for HPI feature..but it's not relevant to mmc controller.
Ok. i will check more..
Best Regards,
Jaehoon Chung
>>> @hans, what do you think?
>>>> Kind regards
>>>> Uffe
>>>>
>>>>> This patch adds a new capability, mmc-broken-hpi, which allows us to
>>>>> mark a broken hpi implementation on the host level.
>>>>>
>>>>> Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
>>>>> ---
>>>>> drivers/mmc/core/host.c | 2 ++
>>>>> drivers/mmc/core/mmc.c | 2 +-
>>>>> include/linux/mmc/host.h | 1 +
>>>>> 3 files changed, 4 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
>>>>> index 6e4c55a..9b63b36 100644
>>>>> --- a/drivers/mmc/core/host.c
>>>>> +++ b/drivers/mmc/core/host.c
>>>>> @@ -270,6 +270,8 @@ int mmc_of_parse(struct mmc_host *host)
>>>>> host->caps |= MMC_CAP_HW_RESET;
>>>>> if (of_property_read_bool(np, "cap-sdio-irq"))
>>>>> host->caps |= MMC_CAP_SDIO_IRQ;
>>>>> + if (of_property_read_bool(np, "mmc-broken-hpi"))
>>>>> + host->caps |= MMC_CAP_BROKEN_HPI;
>>>>> if (of_property_read_bool(np, "full-pwr-cycle"))
>>>>> host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
>>>>> if (of_property_read_bool(np, "keep-power-in-suspend"))
>>>>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
>>>>> index 4dbe3df..9a19562 100644
>>>>> --- a/drivers/mmc/core/mmc.c
>>>>> +++ b/drivers/mmc/core/mmc.c
>>>>> @@ -1592,7 +1592,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>>>>> /*
>>>>> * Enable HPI feature (if supported)
>>>>> */
>>>>> - if (card->ext_csd.hpi) {
>>>>> + if (card->ext_csd.hpi && !(host->caps & MMC_CAP_BROKEN_HPI)) {
>>>>> err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
>>>>> EXT_CSD_HPI_MGMT, 1,
>>>>> card->ext_csd.generic_cmd6_time);
>>>>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
>>>>> index 8dd4d29..20f758e 100644
>>>>> --- a/include/linux/mmc/host.h
>>>>> +++ b/include/linux/mmc/host.h
>>>>> @@ -264,6 +264,7 @@ struct mmc_host {
>>>>> #define MMC_CAP_DRIVER_TYPE_A (1 << 23) /* Host supports Driver Type A */
>>>>> #define MMC_CAP_DRIVER_TYPE_C (1 << 24) /* Host supports Driver Type C */
>>>>> #define MMC_CAP_DRIVER_TYPE_D (1 << 25) /* Host supports Driver Type D */
>>>>> +#define MMC_CAP_BROKEN_HPI (1 << 29) /* Host support for HPI is broken */
>>>>> #define MMC_CAP_CMD23 (1 << 30) /* CMD23 supported. */
>>>>> #define MMC_CAP_HW_RESET (1 << 31) /* Hardware reset */
>>>>>
>>>>> --
>>>>> 2.8.0.rc3
>>>>>
>>>
>>>
>
>
>
next prev parent reply other threads:[~2016-04-19 12:45 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-19 7:12 [PATCHv1 0/2] mmc: Move broken-hpi also to the chipset level Olliver Schinagl
2016-04-19 7:12 ` [PATCH 1/2] mmc: core: Improve marking broken HPI through devicetree Olliver Schinagl
2016-04-19 9:29 ` Ulf Hansson
2016-04-19 9:42 ` Olliver Schinagl
2016-04-19 9:49 ` Jaehoon Chung
2016-04-19 12:20 ` Olliver Schinagl
2016-04-19 12:44 ` Jaehoon Chung [this message]
2016-04-19 9:51 ` Ulf Hansson
2016-04-19 11:22 ` Hans de Goede
2016-04-19 12:45 ` Olliver Schinagl
2016-04-19 19:20 ` Ulf Hansson
2016-04-19 10:52 ` Sergei Shtylyov
2016-04-19 12:21 ` Olliver Schinagl
2016-04-19 13:23 ` Sergei Shtylyov
2016-04-19 7:12 ` [PATCH 2/2] mmc: sunxi: Mark the HPI of the mmc controller broken by default Olliver Schinagl
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=57162849.3070108@samsung.com \
--to=jh80.chung@samsung.com \
--cc=Sudeep.Holla@arm.com \
--cc=adrian.hunter@intel.com \
--cc=chaotian.jing@mediatek.com \
--cc=hdegoede@redhat.com \
--cc=hramrach@gmail.com \
--cc=kuninori.morimoto.gx@renesas.com \
--cc=lars@metafoo.de \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mmc@vger.kernel.org \
--cc=maxime.ripard@free-electrons.com \
--cc=mhocko@suse.com \
--cc=oliver@schinagl.nl \
--cc=sergei.shtylyov@cogentembedded.com \
--cc=ulf.hansson@linaro.org \
--cc=vbyravarasu@nvidia.com \
--cc=wenkai.du@intel.com \
--cc=wens@csie.org \
--cc=wsa+renesas@sang-engineering.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).