lkml.org 
[lkml]   [2019]   [Mar]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 1/4] mmc: mmci: avoid fake busy polling
From
Date
Hi Ulf

I could have a snowball board, I don't remember if it a ux500v1 or v2?
This board has been removed of u-boot mainline, do you have a specific
repository for snowball or what branch do you advise?
do you have a snowball wiki (up-to-date) for flashing...

BR
Ludo
On 3/6/19 10:49 AM, Ulf Hansson wrote:
> On Wed, 6 Mar 2019 at 10:04, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>
>> Hi Ulf
>>
>> On 3/6/19 10:00 AM, Ulf Hansson wrote:
>>> On Tue, 5 Mar 2019 at 17:10, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>>>
>>>> From: Ludovic Barre <ludovic.barre@st.com>
>>>>
>>>> The busy status bit could occurred even if no busy response is
>>>> expected (example cmd11). On sdmmc variant, the busy_detect_flag
>>>> reflects inverted value of d0 state, it's sampled at the end of a
>>>> CMD response and a second time 2 clk cycles after the CMD response.
>>>> To avoid a fake busy, the busy status could be checked and polled
>>>> only if the command has RSP_BUSY flag.
>>>>
>>>> Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
>>>
>>> Before I review this, can you tell what HW you have tested this on?
>>
>> I tested on stm32mp157c (stm32_sdmmc variant)
>
> Okay, I see. So we need to get this tested for the ux500v2 variant as
> well. I try to get some time to do that, soon.
>
> However it seems like you could benefit from having one of those
> boards yourself. It would speed up the process, as you wouldn't have
> to rely on me doing the test. :-) Is there a chance of you could dig
> up some of these old boards from somewhere?
>
> Kind regards
> Uffe
>
>>
>>>
>>> Kind regards
>>> Uffe
>>>
>>>> ---
>>>> drivers/mmc/host/mmci.c | 19 +++++++++++++------
>>>> 1 file changed, 13 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
>>>> index 387ff14..4901b73 100644
>>>> --- a/drivers/mmc/host/mmci.c
>>>> +++ b/drivers/mmc/host/mmci.c
>>>> @@ -1220,12 +1220,13 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
>>>> unsigned int status)
>>>> {
>>>> void __iomem *base = host->base;
>>>> - bool sbc;
>>>> + bool sbc, busy_resp;
>>>>
>>>> if (!cmd)
>>>> return;
>>>>
>>>> sbc = (cmd == host->mrq->sbc);
>>>> + busy_resp = !!(cmd->flags & MMC_RSP_BUSY);
>>>>
>>>> /*
>>>> * We need to be one of these interrupts to be considered worth
>>>> @@ -1239,8 +1240,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
>>>> /*
>>>> * ST Micro variant: handle busy detection.
>>>> */
>>>> - if (host->variant->busy_detect) {
>>>> - bool busy_resp = !!(cmd->flags & MMC_RSP_BUSY);
>>>> + if (busy_resp && host->variant->busy_detect) {
>>>>
>>>> /* We are busy with a command, return */
>>>> if (host->busy_status &&
>>>> @@ -1253,7 +1253,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
>>>> * that the special busy status bit is still set before
>>>> * proceeding.
>>>> */
>>>> - if (!host->busy_status && busy_resp &&
>>>> + if (!host->busy_status &&
>>>> !(status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT)) &&
>>>> (readl(base + MMCISTATUS) & host->variant->busy_detect_flag)) {
>>>>
>>>> @@ -1508,6 +1508,7 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
>>>> {
>>>> struct mmci_host *host = dev_id;
>>>> u32 status;
>>>> + bool busy_resp;
>>>> int ret = 0;
>>>>
>>>> spin_lock(&host->lock);
>>>> @@ -1550,9 +1551,15 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
>>>> }
>>>>
>>>> /*
>>>> - * Don't poll for busy completion in irq context.
>>>> + * Don't poll for:
>>>> + * -busy completion in irq context.
>>>> + * -no busy response expected.
>>>> */
>>>> - if (host->variant->busy_detect && host->busy_status)
>>>> + busy_resp = host->cmd ?
>>>> + !!(host->cmd->flags & MMC_RSP_BUSY) : false;
>>>> +
>>>> + if (host->variant->busy_detect &&
>>>> + (!busy_resp || host->busy_status))
>>>> status &= ~host->variant->busy_detect_flag;
>>>>
>>>> ret = 1;
>>>> --
>>>> 2.7.4
>>>>

\
 
 \ /
  Last update: 2019-03-06 11:10    [W:0.045 / U:6.992 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site