Messages in this thread | | | Subject | Re: [PATCH] i2c: designware: Fix regression when dynamic TAR update is disabled | From | Suravee Suthikulpanit <> | Date | Fri, 10 Feb 2017 13:38:37 +0700 |
| |
On 2/10/17 04:34, De Marchi, Lucas wrote: > On Thu, 2017-02-09 at 22:07 +0200, Andy Shevchenko wrote: >> On Fri, 2017-02-10 at 01:20 +0530, Shah Nehal-Bakulchandra wrote: >>> The following commit causes a regression when dynamic TAR update is >>> disabled: >>> >>> commit 63d0f0a6952a1a02bc4f116b7da7c7887e46efa3 ("i2c: >>> designware: >>> detect when dynamic tar update is possible") >> >> Please, leave just 12 characters, it still enough. >> >>> In such case, the DW_IC_CON_10BITADDR_MASTER is R/W, and is changed >>> by the logic that's trying to detect dynamic TAR update.The original >>> value of DW_IC_CON_10BITADDR_MASTER bit should be restored. > > You are right, thanks for the fix. This may also explains why > 0317e6c (i2c: designware: do not disable adapter after transfer) caused problems > and ended up being reverted. Could you try that on your hardware?
After looking at the patch (i2c: designware: do not disable adapter after transfer), we see that it modifies the i2c_dw_xfer_init(). However, this function is never called on our platform. So, this patch would not have any effects.
At this points, my understanding is there are probably two options here:
1) Keep the commit 63d0f0a6952a (i2c: designware: detect when dynamic tar update is possible) and apply V2 of this patch in 4.10. We might need to back-port the change to v4.9 stable as well.
2) Revert the 63d0f0a6952a (i2c: designware: detect when dynamic tar update is possible) in 4.10, and also in v4.9 stable as well.
Thanks, Suravee
> The dynamic tar update detection was only done as preparation work to allow not > disabling the adapter, which is reverted. We may also just revert this commit > instead of fixing the logic. > > > thanks > Lucas De Marchi >
| |