Re: [PATCH v2 1/2] sdhci: tegra: Implement Tegra specific set_timeout callback

From: Sowjanya Komatineni
Date: Fri Apr 17 2020 - 14:30:04 EST



On 4/17/20 1:04 AM, Ulf Hansson wrote:
External email: Use caution opening links or attachments


On Thu, 16 Apr 2020 at 21:39, Sowjanya Komatineni
<skomatineni@xxxxxxxxxx> wrote:

On 4/16/20 9:29 AM, Sowjanya Komatineni wrote:
On 4/16/20 3:59 AM, Ulf Hansson wrote:
External email: Use caution opening links or attachments


On Wed, 15 Apr 2020 at 19:55, Naresh Kamboju
<naresh.kamboju@xxxxxxxxxx> wrote:
On Fri, 13 Mar 2020 at 06:41, Sowjanya Komatineni
<skomatineni@xxxxxxxxxx> wrote:
Tegra host supports HW busy detection and timeouts based on the
count programmed in SDHCI_TIMEOUT_CONTROL register and max busy
timeout it supports is 11s in finite busy wait mode.

Some operations like SLEEP_AWAKE, ERASE and flush cache through
SWITCH commands take longer than 11s and Tegra host supports
infinite HW busy wait mode where HW waits forever till the card
is busy without HW timeout.

This patch implements Tegra specific set_timeout sdhci_ops to allow
switching between finite and infinite HW busy detection wait modes
based on the device command expected operation time.

Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
---
drivers/mmc/host/sdhci-tegra.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)

diff --git a/drivers/mmc/host/sdhci-tegra.c
b/drivers/mmc/host/sdhci-tegra.c
index a25c3a4..fa8f6a4 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -45,6 +45,7 @@
#define SDHCI_TEGRA_CAP_OVERRIDES_DQS_TRIM_SHIFT 8

#define SDHCI_TEGRA_VENDOR_MISC_CTRL 0x120
+#define SDHCI_MISC_CTRL_ERASE_TIMEOUT_LIMIT BIT(0)
#define SDHCI_MISC_CTRL_ENABLE_SDR104 0x8
#define SDHCI_MISC_CTRL_ENABLE_SDR50 0x10
#define SDHCI_MISC_CTRL_ENABLE_SDHCI_SPEC_300 0x20
@@ -1227,6 +1228,34 @@ static u32 sdhci_tegra_cqhci_irq(struct
sdhci_host *host, u32 intmask)
return 0;
}

+static void tegra_sdhci_set_timeout(struct sdhci_host *host,
+ struct mmc_command *cmd)
+{
+ u32 val;
+
+ /*
+ * HW busy detection timeout is based on programmed data
timeout
+ * counter and maximum supported timeout is 11s which may
not be
+ * enough for long operations like cache flush, sleep
awake, erase.
+ *
+ * ERASE_TIMEOUT_LIMIT bit of VENDOR_MISC_CTRL register allows
+ * host controller to wait for busy state until the card is
busy
+ * without HW timeout.
+ *
+ * So, use infinite busy wait mode for operations that may
take
+ * more than maximum HW busy timeout of 11s otherwise use
finite
+ * busy wait mode.
+ */
+ val = sdhci_readl(host, SDHCI_TEGRA_VENDOR_MISC_CTRL);
+ if (cmd && cmd->busy_timeout >= 11 * HZ)
+ val |= SDHCI_MISC_CTRL_ERASE_TIMEOUT_LIMIT;
+ else
+ val &= ~SDHCI_MISC_CTRL_ERASE_TIMEOUT_LIMIT;
+ sdhci_writel(host, val, SDHCI_TEGRA_VENDOR_MISC_CTRL);
+
+ __sdhci_set_timeout(host, cmd);
kernel build on arm and arm64 architecture failed on stable-rc 4.19
(arm), 5.4 (arm64) and 5.5 (arm64)

drivers/mmc/host/sdhci-tegra.c: In function 'tegra_sdhci_set_timeout':
drivers/mmc/host/sdhci-tegra.c:1256:2: error: implicit declaration of
function '__sdhci_set_timeout'; did you mean
'tegra_sdhci_set_timeout'? [-Werror=implicit-function-declaration]
__sdhci_set_timeout(host, cmd);
^~~~~~~~~~~~~~~~~~~
tegra_sdhci_set_timeout

Full build log,
https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-stable-rc-5.5/DISTRO=lkft,MACHINE=am57xx-evm,label=docker-lkft/83/consoleText

https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-stable-rc-5.4/DISTRO=lkft,MACHINE=juno,label=docker-lkft/158/consoleText

https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-stable-rc-4.19/DISTRO=lkft,MACHINE=am57xx-evm,label=docker-lkft/511/consoleText


- Naresh
Thanks for reporting! What a mess.

It turns out that the commit that was queued for stable that is
causing the above errors, also requires another commit.

The commit that was queued:
5e958e4aacf4 ("sdhci: tegra: Implement Tegra specific set_timeout
callback")

The additional commit needed (which was added in v5.6-rc1):
7d76ed77cfbd ("mmc: sdhci: Refactor sdhci_set_timeout()")

However, the above commit needs a manual backport (quite trivial, but
still) for the relevant stable kernels, to allow it to solve the build
problems.

Greg, Sasha - I suggest you to drop the offending commit from the
stable kernels, for now. I think it's better to let Sowjanya deal with
the backports, then send them in small series instead.

Kind regards
Uffe
Hi Ufee,

Will back-porting below commit cause any issues to other vendors?

7d76ed77cfbd ("mmc: sdhci: Refactor sdhci_set_timeout()")

sdhci-tegra driver in 4.19 is using same sdhci_ops for Tegra114 and
Tegra210 and separate sdhci_ops for T210 started from 4.20.

5e958e4aacf4 ("sdhci: tegra: Implement Tegra specific set_timeout callback")

So above commit can't be applied to 4.19. So probably a separate patch
need to be created to apply for 4.19 and back port above commit along
with its dependency commit (7d76ed77cfbd ("mmc: sdhci: Refactor
sdhci_set_timeout()") for 5.4 and 5.4.
Alright, seems reasonable. Just keep me/Adrian on cc when/if you post
the patches so we can ack them.

Kind regards
Uffe

Sure, will send patches to backport both below changes to 4.19

5e958e4aacf4 ("sdhci: tegra: Implement Tegra specific set_timeout
callback")

7d76ed77cfbd ("mmc: sdhci: Refactor sdhci_set_timeout()")

But on 5.5 and on 5.4.33, patch "mmc: sdhci: Refactor sdhci_set_timeout() already committed but not on 5.4.32 and prior.

So, not sure why kbuild reported error on 5.4 and 5.5 with __sdhci_set_timeout when this patch is already committed on 5.4.33 (26711cc7e064) and 5.5.18 (71bab39fa67d)

Can you please help clarify this?


drivers/mmc/host/sdhci-tegra.c: In function 'tegra_sdhci_set_timeout':
drivers/mmc/host/sdhci-tegra.c:1256:2: error: implicit declaration of
function '__sdhci_set_timeout'; did you mean
'tegra_sdhci_set_timeout'? [-Werror=implicit-function-declaration]
__sdhci_set_timeout(host, cmd);


Thanks

Sowjanya