[PATCH 1/2] Revert "i2c: cadence: Fix the hold bit setting"
Wolfram Sang
wsa at kernel.org
Wed Jul 22 06:29:00 EDT 2020
On Fri, Jul 03, 2020 at 07:25:49PM +0530, Raviteja Narayanam wrote:
> This reverts commit d358def706880defa4c9e87381c5bf086a97d5f9.
>
> There are two issues with "i2c: cadence: Fix the hold bit setting" commit.
>
> 1. In case of combined message request from user space, when the HOLD
> bit is cleared in cdns_i2c_mrecv function, a STOP condition is sent
> on the bus even before the last message is started. This is because when
> the HOLD bit is cleared, the FIFOS are empty and there is no pending
> transfer. The STOP condition should occur only after the last message
> is completed.
>
> 2. The code added by the commit is redundant. Driver is handling the
> setting/clearing of HOLD bit in right way before the commit.
>
> The setting of HOLD bit based on 'bus_hold_flag' is taken care in
> cdns_i2c_master_xfer function even before cdns_i2c_msend/cdns_i2c_recv
> functions.
>
> The clearing of HOLD bit is taken care at the end of cdns_i2c_msend and
> cdns_i2c_recv functions based on bus_hold_flag and byte count.
> Since clearing of HOLD bit is done after the slave address is written to
> the register (writing to address register triggers the message transfer),
> it is ensured that STOP condition occurs at the right time after
> completion of the pending transfer (last message).
>
> Signed-off-by: Raviteja Narayanam <raviteja.narayanam at xilinx.com>
Applied to for-current, thanks!
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20200722/9bfa99d5/attachment.sig>
More information about the linux-arm-kernel
mailing list