From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Date: Thu, 15 Oct 2015 11:03:09 +0000 Subject: Re: [PATCH v2] backlight: pwm: reject legacy pwm request for device defined in dt Message-Id: <20151015110309.GB31804@x1> List-Id: References: <1444652943-19712-1-git-send-email-vladimir_zapolskiy@mentor.com> In-Reply-To: <1444652943-19712-1-git-send-email-vladimir_zapolskiy@mentor.com> MIME-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable To: Vladimir Zapolskiy Cc: Thierry Reding , Jingoo Han , Nicolas Ferre , linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org On Mon, 12 Oct 2015, Vladimir Zapolskiy wrote: > Platform PWM backlight data provided by board's device tree should be > complete enough to successfully request a pwm device using pwm_get() > API. This change fixes a bug, when an arbitrary (first found) PWM is > connected to a "pwm-backlight" compatible device, when explicit PWM > device reference is not given. >=20 > Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt > already describes "pwms" as a required property, instead of blind > selection of a potentially wrong PWM reject legacy PWM device > registration request, leave legacy API only for non-dt cases. >=20 > Based on initial implementation done by Dmitry Eremin-Solenikov. >=20 > Reported-by: Dmitry Eremin-Solenikov > Signed-off-by: Vladimir Zapolskiy > Acked-by: Thierry Reding > Acked-by: Lee Jones > --- > The change is based on lee-backlight/for-backlight-next >=20 > Changes from v1 to v2: > * rebased on top of Nicolas' commit > 68feaca0b13 ("backlight: pwm: Handle EPROBE_DEFER while requesting th= e PWM") >=20 > Links to previous discussions of the change: > * https://patchwork.ozlabs.org/patch/483993/ > * https://patchwork.ozlabs.org/patch/398849/ >=20 > drivers/video/backlight/pwm_bl.c | 19 +++++++++---------- > 1 file changed, 9 insertions(+), 10 deletions(-) Applied, thanks. > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/p= wm_bl.c > index eff379b..ae3c6b6 100644 > --- a/drivers/video/backlight/pwm_bl.c > +++ b/drivers/video/backlight/pwm_bl.c > @@ -271,19 +271,18 @@ static int pwm_backlight_probe(struct platform_devi= ce *pdev) > } > =20 > pb->pwm =3D devm_pwm_get(&pdev->dev, NULL); > - if (IS_ERR(pb->pwm)) { > - ret =3D PTR_ERR(pb->pwm); > - if (ret =3D -EPROBE_DEFER) > - goto err_alloc; > - > + if (IS_ERR(pb->pwm) && PTR_ERR(pb->pwm) !=3D -EPROBE_DEFER > + && !pdev->dev.of_node) { > dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n"); > pb->legacy =3D true; > pb->pwm =3D pwm_request(data->pwm_id, "pwm-backlight"); > - if (IS_ERR(pb->pwm)) { > - dev_err(&pdev->dev, "unable to request legacy PWM\n"); > - ret =3D PTR_ERR(pb->pwm); > - goto err_alloc; > - } > + } > + > + if (IS_ERR(pb->pwm)) { > + ret =3D PTR_ERR(pb->pwm); > + if (ret !=3D -EPROBE_DEFER) > + dev_err(&pdev->dev, "unable to request PWM\n"); > + goto err_alloc; > } > =20 > dev_dbg(&pdev->dev, "got pwm for backlight\n"); --=20 Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog