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* [PATCH] mfd: intel-lpss: Remove D3cold delay
@ 2019-07-05  4:55 Kai-Heng Feng
  2019-07-09 11:46 ` Andy Shevchenko
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Kai-Heng Feng @ 2019-07-05  4:55 UTC (permalink / raw)
  To: lee.jones
  Cc: jarkko.nikula, mika.westerberg, andriy.shevchenko, linux-kernel,
	Kai-Heng Feng

Goodix touchpad may drop its first couple input events when
i2c-designware-platdrv and intel-lpss it connects to took too long to
runtime resume from runtime suspended state.

This issue happens becuase the touchpad has a rather small buffer to
store up to 13 input events, so if the host doesn't read those events in
time (i.e. runtime resume takes too long), events are dropped from the
touchpad's buffer.

The bottleneck is D3cold delay it waits when transitioning from D3cold
to D0, hence remove the delay to make the resume faster. I've tested
some systems with intel-lpss and haven't seen any regression.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202683
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/mfd/intel-lpss-pci.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/mfd/intel-lpss-pci.c b/drivers/mfd/intel-lpss-pci.c
index aed2c0447966..3c271b14e7c6 100644
--- a/drivers/mfd/intel-lpss-pci.c
+++ b/drivers/mfd/intel-lpss-pci.c
@@ -35,6 +35,8 @@ static int intel_lpss_pci_probe(struct pci_dev *pdev,
 	info->mem = &pdev->resource[0];
 	info->irq = pdev->irq;
 
+	pdev->d3cold_delay = 0;
+
 	/* Probably it is enough to set this for iDMA capable devices only */
 	pci_set_master(pdev);
 	pci_try_set_mwi(pdev);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2019-08-12  8:12 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-07-05  4:55 [PATCH] mfd: intel-lpss: Remove D3cold delay Kai-Heng Feng
2019-07-09 11:46 ` Andy Shevchenko
2019-07-25 12:05   ` Lee Jones
2019-07-25 13:42     ` Andy Shevchenko
2019-07-25 13:43 ` Andy Shevchenko
2019-08-12  8:12 ` Lee Jones

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