On Thu, Nov 23, 2023 at 11:10:18AM +0100, Uwe Kleine-König wrote: > Hello Laurent, > > On Thu, Nov 23, 2023 at 11:46:52AM +0200, Laurent Pinchart wrote: > > (CC'ing Bartosz) > > I'm already in discussion with Bart :-) > > > On Tue, Nov 21, 2023 at 02:50:43PM +0100, Uwe Kleine-König wrote: > > > This prepares the pwm driver of the ti-sn65dsi86 to further changes of > > > the pwm core outlined in the commit introducing devm_pwmchip_alloc(). > > > There is no intended semantical change and the driver should behave as > > > before. > > > > > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> > > > --- > > > drivers/gpu/drm/bridge/ti-sn65dsi86.c | 25 ++++++++++++++++--------- > > > 1 file changed, 16 insertions(+), 9 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c > > > index c45c07840f64..cd40530ffd71 100644 > > > --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c > > > +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c > > > @@ -197,7 +197,7 @@ struct ti_sn65dsi86 { > > > DECLARE_BITMAP(gchip_output, SN_NUM_GPIOS); > > > #endif > > > #if defined(CONFIG_PWM) > > > - struct pwm_chip pchip; > > > + struct pwm_chip *pchip; > > > > Dynamic allocation with devm_*() isn't the right solution for lifetime > > issues related to cdev. See my talk at LPC 2022 > > (https://www.youtube.com/watch?v=kW8LHWlJPTU, slides at > > https://lpc.events/event/16/contributions/1227/attachments/1103/2115/20220914-lpc-devm_kzalloc.pdf), > > and Bartosz's talk at LPC 2023 > > (https://lpc.events/event/17/contributions/1627/attachments/1258/2725/Linux%20Plumbers%20Conference%202023.pdf). > > Once the series is completely applied, the pwm_chip isn't allocated > using devm_kzalloc any more. You're only looking at an intermediate > state where I push the broken lifetime tracking from all drivers into a > single function in the core that is then fixed after all drivers are > converted to it. Indeed, I missed that devm_pwm_alloc() got changed later in the series to not call devm_kzalloc(). The naming is quite unfortunate, a devm_*_alloc() function really gives a strong hint that the corresponding cleanup at device remove time will be a free(), not a put() :-S That's pretty confusing for the readers. > If you find issues with the complete series applied, please tell me. One thing I still dislike is forcing drivers to dynamically allocate the pwm_chip series. -- Regards, Laurent Pinchart