On 9/2/23 11:06, Xavier Drudis Ferran wrote: > Is the change of behaviour intended when a clock or reset is not found ? > (see below)
Hi Xavier, I'd say yes, although I haven't seen that... please find my answers below. > > El Wed, Aug 30, 2023 at 10:01:49AM +0200, Fabrice Gasnier deia: >> Make usage of clock and reset bulk API in order to simplify the code >> >> Signed-off-by: Fabrice Gasnier <fabrice.gasn...@foss.st.com> >> --- >> >> drivers/usb/host/ohci-generic.c | 92 +++++++++++---------------------- >> 1 file changed, 29 insertions(+), 63 deletions(-) >> >> diff --git a/drivers/usb/host/ohci-generic.c >> b/drivers/usb/host/ohci-generic.c >> index 2d8d38ce9a40..95aa608d8c19 100644 >> --- a/drivers/usb/host/ohci-generic.c >> +++ b/drivers/usb/host/ohci-generic.c >> @@ -16,75 +16,41 @@ >> >> struct generic_ohci { >> ohci_t ohci; >> - struct clk *clocks; /* clock list */ >> - struct reset_ctl *resets; /* reset list */ >> + struct clk_bulk clocks; /* clock list */ >> + struct reset_ctl_bulk resets; /* reset list */ >> struct phy phy; >> - int clock_count; /* number of clock in clock list */ >> - int reset_count; /* number of reset in reset list */ >> }; >> >> static int ohci_usb_probe(struct udevice *dev) >> { >> struct ohci_regs *regs = dev_read_addr_ptr(dev); >> struct generic_ohci *priv = dev_get_priv(dev); >> - int i, err, ret, clock_nb, reset_nb; >> - >> - err = 0; >> - priv->clock_count = 0; >> - clock_nb = dev_count_phandle_with_args(dev, "clocks", "#clock-cells", >> - 0); >> - if (clock_nb > 0) { >> - priv->clocks = devm_kcalloc(dev, clock_nb, sizeof(struct clk), >> - GFP_KERNEL); >> - if (!priv->clocks) >> - return -ENOMEM; >> - >> - for (i = 0; i < clock_nb; i++) { >> - err = clk_get_by_index(dev, i, &priv->clocks[i]); >> - if (err < 0) >> - break; >> - > > Please note the old code was tolerant of not finding some clocks. It > ignored any clock not found and any other listed after it in the > "clocks" property and enabled the clocks before it. > > The clk_get_bulk() function instead returns an error when any clock in > "clocks" is not found and releases (disables again and frees) those > before it. > > I'm not aware of any case that breaks because of this, but I once saw > a case of ehci not working and ohci working because one of the listed > clocks not being found (ehci called clk_get_bulk(), > clk_enable_blk()). IMHO, the OHCI should have failed too in this example, instead of silently ignoring the error. Hopefully it has probed. The clk_get_bulk() code does a similar job compared to ohci current code. It counts all clock entries. So, when trying to get them, these should be found. Having a clock listed, but it can't be found or taken rather looks like a real error, that needs to be fixed. (e.g. missing config for a clk/reset controller ? Or could it be a bug in such a driver ? Or a miss-configured device-tree ? something else?) Ignoring such error may be miss-leading (as you pointed out, one was working). I hope I don't miss your point. If this is the case, could you point more precise example, or how it used to fail ? > In that case, a fix by ignoring the missing clock > in ehci was rejected, so maybe that criteria applies here as well and > your patch is deemed correct. I don't know. That case won't break now, > I think, either with or without your patch, because after another fix, > that clock will be found. If I understand correctly, this used to fixed elsewhere (e.g. there used to be a real bug fixed) ? > But I don't know if there might be similar > cases. > > I just wanted to point out the change in behaviour. If the change is > intended, then all is fine. IMHO, this should be fine. I hope you agree with this change and the rationale. Best Regards, Fabrice > >> - err = clk_enable(&priv->clocks[i]); >> - if (err && err != -ENOSYS) { >> - dev_err(dev, "failed to enable clock %d\n", i); >> - clk_free(&priv->clocks[i]); >> - goto clk_err; >> - } >> - priv->clock_count++; >> - } >> - } else if (clock_nb != -ENOENT) { >> - dev_err(dev, "failed to get clock phandle(%d)\n", clock_nb); >> - return clock_nb; >> + int err, ret; >> + >> + ret = clk_get_bulk(dev, &priv->clocks); >> + if (ret && ret != -ENOENT) { >> + dev_err(dev, "Failed to get clocks (ret=%d)\n", ret); >> + return ret; >> + } >> + >> + err = clk_enable_bulk(&priv->clocks); >> + if (err) { >> + dev_err(dev, "Failed to enable clocks (err=%d)\n", err); >> + goto clk_err; >> } >> >> - priv->reset_count = 0; >> - reset_nb = dev_count_phandle_with_args(dev, "resets", "#reset-cells", >> - 0); >> - if (reset_nb > 0) { >> - priv->resets = devm_kcalloc(dev, reset_nb, >> - sizeof(struct reset_ctl), >> - GFP_KERNEL); >> - if (!priv->resets) >> - return -ENOMEM; >> - >> - for (i = 0; i < reset_nb; i++) { >> - err = reset_get_by_index(dev, i, &priv->resets[i]); >> - if (err < 0) >> - break; >> - > > Similar here. > >> - err = reset_deassert(&priv->resets[i]); >> - if (err) { >> - dev_err(dev, "failed to deassert reset %d\n", >> i); >> - reset_free(&priv->resets[i]); >> - goto reset_err; >> - } >> - priv->reset_count++; >> - } >> - } else if (reset_nb != -ENOENT) { >> - dev_err(dev, "failed to get reset phandle(%d)\n", reset_nb); >> + err = reset_get_bulk(dev, &priv->resets); >> + if (err && err != -ENOENT) { >> + dev_err(dev, "failed to get resets (err=%d)\n", err); >> goto clk_err; >> } >> >> + err = reset_deassert_bulk(&priv->resets); >> + if (err) { >> + dev_err(dev, "failed to get deassert resets (err=%d)\n", err); >> + goto reset_err; >> + } >> + >> err = generic_setup_phy(dev, &priv->phy, 0); >> if (err) >> goto reset_err; >> @@ -101,13 +67,13 @@ phy_err: >> dev_err(dev, "failed to shutdown usb phy\n"); >> >> reset_err: >> - ret = reset_release_all(priv->resets, priv->reset_count); >> + ret = reset_release_bulk(&priv->resets); >> if (ret) >> - dev_err(dev, "failed to assert all resets\n"); >> + dev_err(dev, "failed to release resets (ret=%d)\n", ret); >> clk_err: >> - ret = clk_release_all(priv->clocks, priv->clock_count); >> + ret = clk_release_bulk(&priv->clocks); >> if (ret) >> - dev_err(dev, "failed to disable all clocks\n"); >> + dev_err(dev, "failed to release clocks (ret=%d)\n", ret); >> >> return err; >> } >> @@ -125,11 +91,11 @@ static int ohci_usb_remove(struct udevice *dev) >> if (ret) >> return ret; >> >> - ret = reset_release_all(priv->resets, priv->reset_count); >> + ret = reset_release_bulk(&priv->resets); >> if (ret) >> return ret; >> >> - return clk_release_all(priv->clocks, priv->clock_count); >> + return clk_release_bulk(&priv->clocks); >> } >> >> static const struct udevice_id ohci_usb_ids[] = { >> -- >> 2.25.1 >>