• Carsten Haitzler's avatar
    i2c: cadence: Fix regression with bus recovery · 8bfd4ec7
    Carsten Haitzler authored
    Commit "i2c: cadence: Add standard bus recovery support" breaks for i2c
    devices that have no pinctrl defined. There is no requirement for this
    to exist in the DT. This has worked perfectly well without this before in
    at least 1 real usage case on hardware (Mali Komeda DPU, Cadence i2c to
    talk to a tda99xx phy). Adding the requirement to have pinctrl set up in
    the device tree (or otherwise be found) is a regression where the whole
    i2c device is lost entirely (in this case dropping entire devices which
    then leads to the drm display stack unable to find the phy for display
    output, thus having no drm display device and so on down the chain).
    
    This converts the above commit to an enhancement if pinctrl can be found
    for the i2c device, providing a timeout on read with recovery, but if not,
    do what used to be done rather than a fatal loss of a device.
    
    This restores the mentioned display devices to their working state again.
    
    Fixes: 58b92424 ("i2c: cadence: Add standard bus recovery support")
    Signed-off-by: default avatarCarsten Haitzler <carsten.haitzler@arm.com>
    Reviewed-by: default avatarShubhrajyoti Datta <shubhrajyoti.datta@amd.com>
    Reviewed-by: default avatarMichael Grzeschik <m.grzeschik@pengutronix.de>
    Acked-by: default avatarMichal Simek <michal.simek@amd.com>
    [wsa: added braces to else-branch]
    Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
    8bfd4ec7
i2c-cadence.c 38.7 KB