On 20 December 2014 at 14:18, Alim Akhtar <alim.akhtar@xxxxxxxxx> wrote:
> Hi Ulf,
>
> On Mon, Dec 8, 2014 at 3:40 PM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
>> On 6 December 2014 at 13:43, Alim Akhtar <alim.akhtar@xxxxxxxxx> wrote:
>>> Hi Ulf,
>>>
>>> On Fri, Dec 5, 2014 at 5:29 PM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
>>>> Instead of having a local hack taking care of sending the tuning
>>>> command and as well to verify the response pattern, let's convert to
>>>> the common mmc_send_tuning() API.
>>>>
>>>> This change affects the Exynos variant, since it's the only one which
>>>> support the dw_mmc's ->execute_tuning() callback.
>>>>
>>>> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
>>>> ---
>>>>
>>
>> Alim, thanks for helping out testing!
>>
>>> With this change HS200 mode does not work on exynos5800 peach-pi board.
>>> I got below error while testing this series:
>>>
>>> mmc0: tuning execution failed
>>> mmc0: error -5 whilst initialising MMC card
>>>
>>> Though, your's next branch with commit _a1d06b4_ works fine in HS200 mode.
>>
>> I was looking into the details of what change my patchset introduces
>> for dw_mmc-exynos. Apparently, dw_mmc-exynos was using the
>> MMC_STOP_TRANSMISSION to end the tuning reqeust (CMD21/19). The new
>> mmc_send_tuning() API doesn't, which also conforms to what the eMMC/SD
>> specifications states.
>>
>> Do you have any idea of why dw_mmc-exynos was using
>> MMC_STOP_TRANSMISSION for CMD19/21?
>>
>> To see if my theory is correct, could you try out the following patch
>> on top of $subject patch?
>> BTW, I have queued patch 1 and 2, from this patchset available on my
>> next branch.
>>
>>
>> From e1ac35bb0e90254275ec7088f41e6e2d59e48367 Mon Sep 17 00:00:00 2001
>> From: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
>> Date: Mon, 8 Dec 2014 10:58:48 +0100
>> Subject: [PATCH] mmc: core: End tuning request with stop command
>>
>> Not to be merged!
>>
>> This patch adds the MMC_STOP_TRANSMISSION command to end a tuning
>> request. For some reason dw_mmc seems to need this to complete the
>> tuning request without errors.
>>
>> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
>> ---
>> drivers/mmc/core/mmc_ops.c | 5 +++++
>> 1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
>> index 3b044c5..aa79e0c 100644
>> --- a/drivers/mmc/core/mmc_ops.c
>> +++ b/drivers/mmc/core/mmc_ops.c
>> @@ -551,6 +551,7 @@ int mmc_send_tuning(struct mmc_host *host)
>> {
>> struct mmc_request mrq = {NULL};
>> struct mmc_command cmd = {0};
>> + struct mmc_command stop = {0};
>> struct mmc_data data = {0};
>> struct scatterlist sg;
>> struct mmc_ios *ios = &host->ios;
>> @@ -576,10 +577,14 @@ int mmc_send_tuning(struct mmc_host *host)
>>
>> mrq.cmd = &cmd;
>> mrq.data = &data;
>> + mrq.stop = &stop;
>>
>> cmd.opcode = opcode;
>> cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
>>
>> + stop.opcode = MMC_STOP_TRANSMISSION;
>> + stop.flags = MMC_RSP_R1B | MMC_CMD_AC;
>> +
>> data.blksz = size;
>> data.blocks = 1;
>> data.flags = MMC_DATA_READ;
>> --
>> 1.9.1
>>
> Sorry for delay in testing this suggested patch, I would say this
> certainly helps, but still I need to change sample phase to make it
> work with generic tuning function.
> So with your's adding STOP_TRANSMISSION command and below change,
> HS200 works well on exynos5800
>
> diff --git a/arch/arm/boot/dts/exynos5800-peach-pi.dts
> b/arch/arm/boot/dts/exynos5800-peach-pi.dts
> index e8fdda8..e0f0337 100644
> --- a/arch/arm/boot/dts/exynos5800-peach-pi.dts
> +++ b/arch/arm/boot/dts/exynos5800-peach-pi.dts
> @@ -555,7 +555,7 @@
> card-detect-delay = <200>;
> clock-frequency = <400000000>;
> samsung,dw-mshc-ciu-div = <3>;
> - samsung,dw-mshc-sdr-timing = <0 4>;
> + samsung,dw-mshc-sdr-timing = <2 4>;
>
> This basically change the clock-sample phase with which the tuning
> process starts.
>
> I didn't find anything is exynos documentations which suggest
> STOP_TRANSMISSION is needed, may be Seungwon might be know as he wrote
> this.
>
> Are you ok to add STOP_TRANSMISSION in generic tuning code (probably
> with a quirk, so that other hosts are still happy)?
No, I don't want that.
If special treatment are needed for dw_mmc to handle a tuning request,
dw_mmc should be able to take care by itself. How about below patch,
do you think that could work?
>From c2e5783beaa322178f2336b4bff4bdf13da76f56 Mon Sep 17 00:00:00 2001
From: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Date: Mon, 22 Dec 2014 15:24:14 +0100
Subject: [PATCH] mmc: dw_mmc: Generate stop commands for failed tuning
requests
It's seems like dw_mmc internal logic expects failed data transfers to
be ended using a stop command. Let the tuning requests also fall into
this category, since there are data transfer involved.
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
---
drivers/mmc/host/dw_mmc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index a1b80e5..976382db 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -314,7 +314,9 @@ static u32 dw_mci_prep_stop_abort(struct dw_mci
*host, struct mmc_command *cmd)
if (cmdr == MMC_READ_SINGLE_BLOCK ||
cmdr == MMC_READ_MULTIPLE_BLOCK ||
cmdr == MMC_WRITE_BLOCK ||
- cmdr == MMC_WRITE_MULTIPLE_BLOCK) {
+ cmdr == MMC_WRITE_MULTIPLE_BLOCK ||
+ cmdr == MMC_SEND_TUNING_BLOCK ||
+ cmdr == MMC_SEND_TUNING_BLOCK_HS200) {
stop->opcode = MMC_STOP_TRANSMISSION;
stop->arg = 0;
stop->flags = MMC_RSP_R1B | MMC_CMD_AC;
--
1.9.1
> If so, I can send the above DT change as a fix.
Please do!
Again, I appreciate all your efforts in helping out!
Kind regards
Uffe
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