On Mon, Apr 23, 2018 at 11:03 AM, Alexander Monakov <amonakov@xxxxxxxxx> wrote: > On Mon, 23 Apr 2018, Ben Gardner wrote: >> I think we need to be smarter about which boards have the >> IC_ENABLE_STATUS register, but I don't know enough about the various >> supported Designware I2C controller implementations to suggest an >> approach. > > We can assume that 1.1.5 (the IP rev. in your Atom) and newer have it, > if we don't find a better solution. > > Does changing __i2c_dw_enable to __i2c_dw_enable_and_wait in i2c_dw_xfer > on its own fix the problem for you? No. That change did not fix it. > If that works, I think a possible solution might be to always poll on > disabling as recommended by docs, but do it asynchronously to avoid the > slowdown that prompted the elision we have now. Although in that case > I'm not sure why current code leads to a failure, as i2c_dw_xfer_init > performs the polling anyway. > > Can you add printks in dw_readl/dw_writel and maybe a few extra printks > in their callers to see what accesses are being made, and share the > resulting trace? Sure. The log is below. I filtered out the logs from other buses and removed repetitive messages. > What are the devices being accessed on the i2c bus in your case? On bus 18.3, there is a TMP75C (temperature sensor) and a M24C02 EEPROM. I should note that I also have one I2C device (RTC) on bus 18.2, but that never has had issues. [ 0.227955] i2c-designware-pci 0000:00:18.3: i2c_dw_init_master: dw_readl(0xfc) => 0x44570140 [ 0.227960] i2c-designware-pci 0000:00:18.3: i2c_dw_init_master: dw_readl(0xf4) => 0x00ffffee [ 0.227963] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable: dw_writel(0x6c, 0x00000000) [ 0.227967] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable_and_wait: dw_readl(0x9c) => 0x00000000 [ 0.227970] i2c-designware-pci 0000:00:18.3: i2c_dw_init_master: dw_writel(0x14, 0x00000200) [ 0.227973] i2c-designware-pci 0000:00:18.3: i2c_dw_init_master: dw_writel(0x18, 0x00000200) [ 0.227976] i2c-designware-pci 0000:00:18.3: i2c_dw_init_master: dw_writel(0x1c, 0x00000055) [ 0.227979] i2c-designware-pci 0000:00:18.3: i2c_dw_init_master: dw_writel(0x20, 0x00000099) [ 0.227982] i2c-designware-pci 0000:00:18.3: i2c_dw_init_master: dw_readl(0xf8) => 0x3131352a [ 0.227985] i2c-designware-pci 0000:00:18.3: COMP_VERISON: 0x3131352a [ 0.227987] i2c-designware-pci 0000:00:18.3: i2c_dw_init_master: dw_writel(0x7c, 0x00010006) [ 0.227990] i2c-designware-pci 0000:00:18.3: i2c_dw_configure_fifo_master: dw_writel(0x3c, 0x00000010) [ 0.227993] i2c-designware-pci 0000:00:18.3: i2c_dw_configure_fifo_master: dw_writel(0x38, 0x00000000) [ 0.227996] i2c-designware-pci 0000:00:18.3: i2c_dw_configure_fifo_master: dw_writel(0x0, 0x00000065) [ 0.227999] i2c-designware-pci 0000:00:18.3: i2c_dw_disable_int: dw_writel(0x30, 0x00000000) [ 0.229223] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer: msgs: 2 [ 0.229228] i2c-designware-pci 0000:00:18.3: i2c_dw_wait_bus_not_busy: dw_readl(0x70) => 0x00000006 [ 0.229231] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable: dw_writel(0x6c, 0x00000000) [ 0.229234] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable_and_wait: dw_readl(0x9c) => 0x00000000 [ 0.229239] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_init: dw_readl(0x0) => 0x00000065 [ 0.229242] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_init: dw_writel(0x0, 0x00000065) [ 0.229245] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_init: dw_writel(0x4, 0x00000057) [ 0.229248] i2c-designware-pci 0000:00:18.3: i2c_dw_disable_int: dw_writel(0x30, 0x00000000) [ 0.229251] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable: dw_writel(0x6c, 0x00000001) [ 0.229254] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_init: dw_readl(0x40) => 0x00000000 [ 0.229257] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_init: dw_writel(0x30, 0x00000254) [ 0.229336] i2c-designware-pci 0000:00:18.3: i2c_dw_isr: dw_readl(0x6c) => 0x00000001 [ 0.229340] i2c-designware-pci 0000:00:18.3: i2c_dw_isr: dw_readl(0x34) => 0x00000210 [ 0.229343] i2c-designware-pci 0000:00:18.3: i2c_dw_read_clear_intrbits: dw_readl(0x2c) => 0x00000210 [ 0.229347] i2c-designware-pci 0000:00:18.3: i2c_dw_read_clear_intrbits: dw_readl(0x60) => 0x00000001 [ 0.229350] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_readl(0x74) => 0x00000000 [ 0.229353] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_readl(0x78) => 0x00000000 [ 0.229356] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_writel(0x10, 0x00000000) [ 0.229359] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_readl(0x74) => 0x00000001 [ 0.229362] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_readl(0x78) => 0x00000000 [ 0.229365] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_writel(0x10, 0x00000700) [ 0.229368] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_writel(0x30, 0x00000244) [ 0.229435] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable: dw_writel(0x6c, 0x00000000) [ 0.229439] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable_and_wait: dw_readl(0x9c) => 0x00000001 [ 0.229701] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable: dw_writel(0x6c, 0x00000000) [ 0.229705] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable_and_wait: dw_readl(0x9c) => 0x00000000 [ 0.233943] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer: msgs: 2 [ 0.233948] i2c-designware-pci 0000:00:18.3: i2c_dw_wait_bus_not_busy: dw_readl(0x70) => 0x00000006 [ 0.233952] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable: dw_writel(0x6c, 0x00000000) [ 0.233955] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable_and_wait: dw_readl(0x9c) => 0x00000000 [ 0.233960] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_init: dw_readl(0x0) => 0x00000065 [ 0.233963] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_init: dw_writel(0x0, 0x00000065) [ 0.233966] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_init: dw_writel(0x4, 0x00000048) [ 0.233969] i2c-designware-pci 0000:00:18.3: i2c_dw_disable_int: dw_writel(0x30, 0x00000000) [ 0.233972] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable: dw_writel(0x6c, 0x00000001) [ 0.233975] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_init: dw_readl(0x40) => 0x00000000 [ 0.233978] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_init: dw_writel(0x30, 0x00000254) [ 0.233990] i2c-designware-pci 0000:00:18.3: i2c_dw_isr: dw_readl(0x6c) => 0x00000001 [ 0.233994] i2c-designware-pci 0000:00:18.3: i2c_dw_isr: dw_readl(0x34) => 0x00000210 [ 0.233997] i2c-designware-pci 0000:00:18.3: i2c_dw_read_clear_intrbits: dw_readl(0x2c) => 0x00000210 [ 0.234001] i2c-designware-pci 0000:00:18.3: i2c_dw_read_clear_intrbits: dw_readl(0x60) => 0x00000001 [ 0.234005] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_readl(0x74) => 0x00000000 [ 0.234008] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_readl(0x78) => 0x00000000 [ 0.234011] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_writel(0x10, 0x00000001) [ 0.234015] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_readl(0x74) => 0x00000001 [ 0.234018] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_readl(0x78) => 0x00000000 [ 0.234021] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_writel(0x10, 0x00000700) [ 0.234024] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer_msg: dw_writel(0x30, 0x00000244) [ 0.234035] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable: dw_writel(0x6c, 0x00000000) [ 0.234039] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable_and_wait: dw_readl(0x9c) => 0x00000001 [ 0.234301] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable: dw_writel(0x6c, 0x00000000) [ 0.234304] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable_and_wait: dw_readl(0x9c) => 0x00000001 ( removed repeated messages ) [ 0.259875] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable: dw_writel(0x6c, 0x00000000) [ 0.259879] i2c-designware-pci 0000:00:18.3: __i2c_dw_enable_and_wait: dw_readl(0x9c) => 0x00000001 [ 0.260143] i2c-designware-pci 0000:00:18.3: timeout in disabling adapter [ 0.260147] i2c-designware-pci 0000:00:18.3: i2c_dw_xfer: msgs: 1 [ 0.260151] i2c-designware-pci 0000:00:18.3: i2c_dw_wait_bus_not_busy: dw_readl(0x70) => 0x00000027 [ 0.261266] i2c-designware-pci 0000:00:18.3: i2c_dw_wait_bus_not_busy: dw_readl(0x70) => 0x00000027 ( removed repeated messages ) [ 0.288501] i2c-designware-pci 0000:00:18.3: i2c_dw_wait_bus_not_busy: dw_readl(0x70) => 0x00000027 [ 0.288505] i2c-designware-pci 0000:00:18.3: timeout waiting for bus ready
