From: arend@broadcom•com (Arend van Spriel)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2] mmc: sunxi: Don't start commands while the card is busy
Date: Tue, 28 Jul 2015 21:22:30 +0200 [thread overview]
Message-ID: <55B7D676.1020800@broadcom.com> (raw)
In-Reply-To: <CAPDyKFoNe0bghfSXs48stHzZToTc7Hjd5gVPy-VbDF8bzdVVMQ@mail.gmail.com>
On 07/21/2015 02:15 PM, Ulf Hansson wrote:
> On 10 July 2015 at 17:14, Hans de Goede <hdegoede@redhat•com> wrote:
>> Some sdio wifi modules have not been working reliable with the sunxi-mmc
>> host code. This turns out to be caused by it starting new commands while
>> the card signals that it is still busy processing a previous command.
>
> Which are those commands? Or more interesting, which response types do
> these commands expect?
> I don't think this is a sunxi specific issue, I have seen similar
> issues for other host controllers.
Indeed. A similar fix was needed for dw_mmc host controller.
> I am thinking that perhaps this should be managed by the mmc core
> instead of local hacks to sunxi. Potentially we could make the core to
> invoke the already existing host_ops->card_busy() callback when
> needed...
The problem here is that there are a number of host controllers out
there not implementing that callback. That may be because the hardware
is dealing properly with busy signalling, but I would not bet on that.
Regards,
Arend
> Within this context, could I ask whether you controller supports IRQ
> based HW-busy detection? Or you need polling of the status register?
>
>>
>> This commit fixes this, thereby fixing the wifi reliability issues on
>> the Cubietruck and other sunxi boards using sdio wifi.
>>
>> Reported-by: Eugene K <sigintmailru@gmail•com>
>> Suggested-by: Eugene K <sigintmailru@gmail•com>
>> Cc: Eugene K <sigintmailru@gmail•com>
>> Cc: Arend van Spriel <arend@broadcom•com>
>> Signed-off-by: Hans de Goede <hdegoede@redhat•com>
>> ---
>> Changes in v2:
>> -Properly accredit Eugene K for coming up with the fix for this
>> ---
>> drivers/mmc/host/sunxi-mmc.c | 32 ++++++++++++++++++++++++++++++++
>> 1 file changed, 32 insertions(+)
>>
>> diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
>> index 4d3e1ff..daa90b7 100644
>> --- a/drivers/mmc/host/sunxi-mmc.c
>> +++ b/drivers/mmc/host/sunxi-mmc.c
>> @@ -289,6 +289,24 @@ static int sunxi_mmc_init_host(struct mmc_host *mmc)
>> return 0;
>> }
>>
>> +/* Wait for card to report ready before starting a new cmd */
>> +static int sunxi_mmc_wait_card_ready(struct sunxi_mmc_host *host)
>> +{
>> + unsigned long expire = jiffies + msecs_to_jiffies(500);
>> + u32 rval;
>> +
>> + do {
>> + rval = mmc_readl(host, REG_STAS);
>> + } while (time_before(jiffies, expire) && (rval & SDXC_CARD_DATA_BUSY));
>> +
>> + if (rval & SDXC_CARD_DATA_BUSY) {
>> + dev_err(mmc_dev(host->mmc), "Error R1 ready timeout\n");
>> + return -EIO;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> static void sunxi_mmc_init_idma_des(struct sunxi_mmc_host *host,
>> struct mmc_data *data)
>> {
>> @@ -383,6 +401,8 @@ static void sunxi_mmc_send_manual_stop(struct sunxi_mmc_host *host,
>> u32 arg, cmd_val, ri;
>> unsigned long expire = jiffies + msecs_to_jiffies(1000);
>>
>> + sunxi_mmc_wait_card_ready(host);
>> +
>> cmd_val = SDXC_START | SDXC_RESP_EXPIRE |
>> SDXC_STOP_ABORT_CMD | SDXC_CHECK_RESPONSE_CRC;
>>
>> @@ -597,6 +617,11 @@ static int sunxi_mmc_oclk_onoff(struct sunxi_mmc_host *host, u32 oclk_en)
>> {
>> unsigned long expire = jiffies + msecs_to_jiffies(250);
>> u32 rval;
>> + int ret;
>> +
>> + ret = sunxi_mmc_wait_card_ready(host);
>> + if (ret)
>> + return ret;
>>
>> rval = mmc_readl(host, REG_CLKCR);
>> rval &= ~(SDXC_CARD_CLOCK_ON | SDXC_LOW_POWER_ON);
>> @@ -785,6 +810,13 @@ static void sunxi_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
>> return;
>> }
>>
>> + ret = sunxi_mmc_wait_card_ready(host);
>> + if (ret) {
>> + mrq->cmd->error = ret;
>> + mmc_request_done(mmc, mrq);
>> + return;
>> + }
>> +
>> if (data) {
>> ret = sunxi_mmc_map_dma(host, data);
>> if (ret < 0) {
>> --
>> 2.4.3
>>
>
> Kind regards
> Uffe
>
next prev parent reply other threads:[~2015-07-28 19:22 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-10 15:14 [PATCH v2] mmc: sunxi: Don't start commands while the card is busy Hans de Goede
2015-07-20 8:00 ` Maxime Ripard
2015-07-20 15:23 ` [linux-sunxi] " Hans de Goede
2015-07-24 8:26 ` Maxime Ripard
2015-07-21 12:15 ` Ulf Hansson
2015-07-28 19:22 ` Arend van Spriel [this message]
2015-08-01 9:01 ` Hans de Goede
2015-08-25 12:05 ` Ulf Hansson
2015-08-25 12:09 ` Hans de Goede
2015-08-25 13:58 ` Ulf Hansson
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