| Message ID | 20210419042722.27554-2-alice.guo@oss.nxp.com |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC,v1,1/3] drivers: soc: add support for soc_device_match returning -EPROBE_DEFER | expand |
> -----Original Message----- > From: Dominique MARTINET <dominique.martinet@atmark-techno.com> > Sent: 2021年4月19日 12:49 > To: Alice Guo (OSS) <alice.guo@oss.nxp.com> > Cc: gregkh@linuxfoundation.org; rafael@kernel.org; Horia Geanta > <horia.geanta@nxp.com>; Aymen Sghaier <aymen.sghaier@nxp.com>; > herbert@gondor.apana.org.au; davem@davemloft.net; tony@atomide.com; > geert+renesas@glider.be; mturquette@baylibre.com; sboyd@kernel.org; > vkoul@kernel.org; peter.ujfalusi@gmail.com; a.hajda@samsung.com; > narmstrong@baylibre.com; robert.foss@linaro.org; airlied@linux.ie; > daniel@ffwll.ch; khilman@baylibre.com; tomba@kernel.org; jyri.sarha@iki.fi; > joro@8bytes.org; will@kernel.org; mchehab@kernel.org; > ulf.hansson@linaro.org; adrian.hunter@intel.com; kishon@ti.com; > kuba@kernel.org; linus.walleij@linaro.org; Roy Pledge <roy.pledge@nxp.com>; > Leo Li <leoyang.li@nxp.com>; ssantosh@kernel.org; matthias.bgg@gmail.com; > edubezval@gmail.com; j-keerthy@ti.com; balbi@kernel.org; > linux@prisktech.co.nz; stern@rowland.harvard.edu; wim@linux-watchdog.org; > linux@roeck-us.net; linux-kernel@vger.kernel.org; linux-crypto@vger.kernel.org; > linux-omap@vger.kernel.org; linux-renesas-soc@vger.kernel.org; > linux-clk@vger.kernel.org; dmaengine@vger.kernel.org; > dri-devel@lists.freedesktop.org; linux-amlogic@lists.infradead.org; > linux-arm-kernel@lists.infradead.org; iommu@lists.linux-foundation.org; > linux-media@vger.kernel.org; linux-mmc@vger.kernel.org; > netdev@vger.kernel.org; linux-phy@lists.infradead.org; > linux-gpio@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; > linux-staging@lists.linux.dev; linux-mediatek@lists.infradead.org; > linux-pm@vger.kernel.org; linux-usb@vger.kernel.org; > linux-watchdog@vger.kernel.org > Subject: Re: [RFC v1 PATCH 1/3] drivers: soc: add support for soc_device_match > returning -EPROBE_DEFER > > First comment overall for the whole serie: > Since it is the solution I had suggested when I reported the problem[1] I have no > qualm on the approach, comments for individual patches follow. > > [1] http://lore.kernel.org/r/YGGZJjAxA1IO+/VU@atmark-techno.com > > > Alice Guo (OSS) wrote on Mon, Apr 19, 2021 at 12:27:20PM +0800: > > From: Alice Guo <alice.guo@nxp.com> > > > > In i.MX8M boards, the registration of SoC device is later than caam > > driver which needs it. Caam driver needs soc_device_match to provide > > -EPROBE_DEFER when no SoC device is registered and no > > early_soc_dev_attr. > > This patch should be last in the set: you can't have soc_device_match return an > error before its callers handle it. > > > Signed-off-by: Alice Guo <alice.guo@nxp.com> > > As the one who reported the problem I would have been appreciated being at > least added to Ccs... I only happened to notice you posted this by chance. Sorry. I will Cc you next time. > There is also not a single Fixes tag -- I believe this commit should have Fixes: > 7d981405d0fd ("soc: imx8m: change to use platform driver") but I'm not sure > how such tags should be handled in case of multiple patches fixing something. I only mentioned "soc: imx8m: change to use platform driver" in cover letter. If it is acceptable to make such a modification, I will send non-RFC and add Fixes tag. Best Regards, Alice > -- > Dominique
On Mon, Apr 19, 2021 at 10:20:13AM +0200, Geert Uytterhoeven wrote: > Hi Alice, > > CC Arnd (soc_device_match() author) > > On Mon, Apr 19, 2021 at 6:28 AM Alice Guo (OSS) <alice.guo@oss.nxp.com> wrote: > > From: Alice Guo <alice.guo@nxp.com> > > > > In i.MX8M boards, the registration of SoC device is later than caam > > driver which needs it. Caam driver needs soc_device_match to provide > > -EPROBE_DEFER when no SoC device is registered and no > > early_soc_dev_attr. > > I'm wondering if this is really a good idea: soc_device_match() is a > last-resort low-level check, and IMHO should be made available early on, > so there is no need for -EPROBE_DEFER. > > > > > Signed-off-by: Alice Guo <alice.guo@nxp.com> > > Thanks for your patch! > > > --- a/drivers/base/soc.c > > +++ b/drivers/base/soc.c > > @@ -110,6 +110,7 @@ static void soc_release(struct device *dev) > > } > > > > static struct soc_device_attribute *early_soc_dev_attr; > > +static bool soc_dev_attr_init_done = false; > > Do you need this variable? > > > > > struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr) > > { > > @@ -157,6 +158,7 @@ struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr > > return ERR_PTR(ret); > > } > > > > + soc_dev_attr_init_done = true; > > return soc_dev; > > > > out3: > > @@ -246,6 +248,9 @@ const struct soc_device_attribute *soc_device_match( > > if (!matches) > > return NULL; > > > > + if (!soc_dev_attr_init_done && !early_soc_dev_attr) > > if (!soc_bus_type.p && !early_soc_dev_attr) There is one place checking this already. We could wrap it in a helper function: static bool device_init_done(void) { return soc_bus_type.p ? true : false; } regards, dan carpenter
diff --git a/drivers/base/soc.c b/drivers/base/soc.c index 0af5363a582c..12a22f9cf5c8 100644 --- a/drivers/base/soc.c +++ b/drivers/base/soc.c @@ -110,6 +110,7 @@ static void soc_release(struct device *dev) } static struct soc_device_attribute *early_soc_dev_attr; +static bool soc_dev_attr_init_done = false; struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr) { @@ -157,6 +158,7 @@ struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr return ERR_PTR(ret); } + soc_dev_attr_init_done = true; return soc_dev; out3: @@ -246,6 +248,9 @@ const struct soc_device_attribute *soc_device_match( if (!matches) return NULL; + if (!soc_dev_attr_init_done && !early_soc_dev_attr) + return ERR_PTR(-EPROBE_DEFER); + while (!ret) { if (!(matches->machine || matches->family || matches->revision || matches->soc_id))