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
Kind regards
Uffe
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