From: Andrey Utkin Date: Sat, 22 Oct 2016 15:34:36 +0000 (-0200) Subject: media: solo6x10: fix lockup by avoiding delayed register write X-Git-Tag: firefly_0821_release~176^2~4^2~6^2~11 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=44685f03dd5648407c5cf8d5a1a0eefd24036a27;p=firefly-linux-kernel-4.4.55.git media: solo6x10: fix lockup by avoiding delayed register write commit 5fc4b067ec082c3127e0156f800769b7e0dce078 upstream. This fixes a lockup at device probing which happens on some solo6010 hardware samples. This is a regression introduced by commit e1ceb25a1569 ("[media] SOLO6x10: remove unneeded register locking and barriers") The observed lockup happens in solo_set_motion_threshold() called from solo_motion_config(). This extra "flushing" is not fundamentally needed for every write, but apparently the code in driver assumes such behaviour at last in some places. Actual fix was proposed by Hans Verkuil. Fixes: e1ceb25a1569 ("[media] SOLO6x10: remove unneeded register locking and barriers") Signed-off-by: Andrey Utkin Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/media/pci/solo6x10/solo6x10.h b/drivers/media/pci/solo6x10/solo6x10.h index 4ab6586c0467..f53e59e9c0ea 100644 --- a/drivers/media/pci/solo6x10/solo6x10.h +++ b/drivers/media/pci/solo6x10/solo6x10.h @@ -286,7 +286,10 @@ static inline u32 solo_reg_read(struct solo_dev *solo_dev, int reg) static inline void solo_reg_write(struct solo_dev *solo_dev, int reg, u32 data) { + u16 val; + writel(data, solo_dev->reg_base + reg); + pci_read_config_word(solo_dev->pdev, PCI_STATUS, &val); } static inline void solo_irq_on(struct solo_dev *dev, u32 mask)