Hey,

On 12-08-15 14:35, Hans de Goede wrote:

Hi,

On 12-08-15 14:23, Michal Suchanek wrote:

quoted

When core does not set the MMC_QUIRK_BROKEN_CLK_GATING flag enable
automatic hardware controlled clock gating on the mmc interface.

Signed-off-by: Michal Suchanek <redacted>

In general this looks good, but I wonder how intensively this has
been tested ?

It doesn't matter actually, it took some time longer, but the mmc still 
craps out even with Michal's 3 patches. I'll revert hans's earlier patch 
again and do a bit more extensive testing.

Also given the long latencies when using manual
clock on/off support, have you done any testing to check what
sort of latencies this adds, e.g. Both with and without
the patch, dump all the filesystem caches:

echo 3 > /proc/sys/vm/drop_caches

And then do:

time cat /some/small/file/on/the/sdcard

Do this at least 3 time both with and without the patch, and see
if there are any noticable differences ?

Regards,

Hans

quoted

---
  drivers/mmc/host/sunxi-mmc.c | 7 ++++++-
  1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
index f808a02..443cab5 100644
--- a/drivers/mmc/host/sunxi-mmc.c
+++ b/drivers/mmc/host/sunxi-mmc.c

@@ -601,8 +601,13 @@ static int sunxi_mmc_oclk_onoff(struct 

sunxi_mmc_host *host, u32 oclk_en)
      rval = mmc_readl(host, REG_CLKCR);
      rval &= ~(SDXC_CARD_CLOCK_ON | SDXC_LOW_POWER_ON);

-    if (oclk_en)
+    if (oclk_en) {
          rval |= SDXC_CARD_CLOCK_ON;
+        if (!host->mmc->card ||
+             !(host->mmc->card->quirks & MMC_QUIRK_BROKEN_CLK_GATING))
+
+            rval |= SDXC_LOW_POWER_ON;
+    }

      start = jiffies;
      end = start + msecs_to_jiffies(750);