user/sven/linux.git/drivers/i2c, branch v4.4.148

i2c: imx: Fix reinit_completion() use

2018-08-09T10:19:28Z

commit 9f9e3e0d4dd3338b3f3dde080789f71901e1e4ff upstream. Make sure to call reinit_completion() before dma is started to avoid race condition where reinit_completion() is called after complete() and before wait_for_completion_timeout(). Signed-off-by: Esben Haabendal Fixes: ce1a78840ff7 ("i2c: imx: add DMA support for freescale i2c driver") Reviewed-by: Uwe Kleine-König Signed-off-by: Wolfram Sang Cc: stable@kernel.org Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman

i2c: rcar: fix resume by always initializing registers before transfer

2018-07-11T14:03:47Z

commit ae481cc139658e89eb3ea671dd00b67bd87f01a3 upstream. Resume failed because of uninitialized registers. Instead of adding a resume callback, we simply initialize registers before every transfer. This lightweight change is more robust and will keep us safe if we ever need support for power domains or dynamic frequency changes. Signed-off-by: Wolfram Sang Acked-by: Kuninori Morimoto Signed-off-by: Wolfram Sang Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

i2c: rcar: revoke START request early

2018-06-06T14:46:22Z

commit 52df445f29b79006d8b2dcd129152987c0d3bd64 upstream. If we don't clear START generation as soon as possible, it may cause another message to be generated, e.g. when receiving NACK in address phase. To keep the race window as small as possible, we clear it right at the beginning of the interrupt. We don't need any checks since we always want to stop START and STOP generation on the next occasion after we started it. This patch improves the situation but sadly does not completely fix it. It is still to be researched if we can do better given this HW design. Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang Signed-off-by: Fabrizio Castro Reviewed-by: Biju Das Signed-off-by: Greg Kroah-Hartman

i2c: rcar: check master irqs before slave irqs

2018-06-06T14:46:22Z

commit c3be0af15959e11fa535d5332ab3d7cf34abd09b upstream. Due to the HW design, master IRQs are timing critical, so give them precedence over slave IRQ. Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang Signed-off-by: Fabrizio Castro Reviewed-by: Biju Das Signed-off-by: Greg Kroah-Hartman

i2c: rcar: don't issue stop when HW does it automatically

2018-06-06T14:46:22Z

commit d89667b14f9d13b684287f6189ca209af5feee43 upstream. The manual says (55.4.8.6) that HW does automatically send STOP after NACK was received. My measuerments confirm that. Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang Signed-off-by: Fabrizio Castro Reviewed-by: Biju Das Signed-off-by: Greg Kroah-Hartman

i2c: rcar: init new messages in irq

2018-06-06T14:46:22Z

commit cc21d0b4b62e41e5013d763adade5ea4462c33a4 upstream. Setting up new messages was done in process context while handling a message was in interrupt context. Because of the HW design, this IP core is sensitive to timing, so the context switches were too expensive. Move this setup to interrupt context as well. In my test setup, this fixed the occasional 'data byte sent twice' issue which a number of people have seen. It also fixes to send REP_START after a read message which was wrongly send as a STOP + START sequence before. Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang Signed-off-by: Fabrizio Castro Reviewed-by: Chris Paterson Signed-off-by: Greg Kroah-Hartman

i2c: rcar: refactor setup of a msg

2018-06-06T14:46:22Z

commit b9d0684c79c4b9d30ce0d47d3270493dd0e76e59 upstream. We want to reuse this function later. Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang Signed-off-by: Fabrizio Castro Reviewed-by: Chris Paterson Signed-off-by: Greg Kroah-Hartman

i2c: rcar: remove spinlock

2018-06-06T14:46:22Z

commit ff2316b87a336bff940939cd9fc56287ed48e578 upstream. After making sure to reinit the HW and clear interrupts in the timeout case, we know that interrupts are always disabled in the sections protected by the spinlock. Thus, we can simply remove it which is a preparation for further refactoring. While here, rename the timeout variable to time_left which is way more readable. Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang Signed-off-by: Fabrizio Castro Reviewed-by: Chris Paterson Signed-off-by: Greg Kroah-Hartman

i2c: rcar: remove unused IOERROR state

2018-06-06T14:46:22Z

commit 90f779e565bdc18dd4f79d81cf11f43a7266010b upstream. Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang Signed-off-by: Fabrizio Castro Reviewed-by: Chris Paterson Signed-off-by: Greg Kroah-Hartman

i2c: rcar: rework hw init

2018-06-06T14:46:22Z

commit 2c78cdc1c06308a59d6ed4145cdba73fdeff8c0d upstream. We don't need to init HW before every transfer since we know the HW state then. HW init at probe time is enough. While here, add setting the clock register which belongs to init HW. Also, set MDBS bit since not setting it is prohibited according to the manual. Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang Signed-off-by: Fabrizio Castro Reviewed-by: Chris Paterson Signed-off-by: Greg Kroah-Hartman