Hi,
On Tue, 20 Jun 2017 12:56:48 +0000 Patrice CHOTARD wrote:
> Hi Lothar
>
> On 06/20/2017 02:06 PM, Lothar Waßmann wrote:
> > Hi,
> >
> > On Tue, 20 Jun 2017 11:59:09 +0200 patrice.chot...@st.com wrote:
> >> From: Patrice Chotard <patrice.chot...@st.com>
> >>
> >> use array to save enabled clocks reference in order to
> >> disabled them in case of error during probe() or during
> >> driver removal.
> >>
> >> Signed-off-by: Patrice Chotard <patrice.chot...@st.com>
> >> ---
> >> v7: _ replace clk_count() by ofnode_count_phandle_with_args()
> >>
> >> v6: _ none
> >>
> >> v5: _ none
> >>
> >> v4: _ use generic_phy_valid() before generic_phy_exit() call
> >>
> >> v3: _ extract in this patch the CLOCK support add-on from previous
> >> patch 5
> >> _ keep enabled clocks reference in list in order to
> >> disable clocks in error path or in .remove callback
> >>
> >> v2: _ add error path management
> >> _ add .remove callback
> >>
> >> drivers/usb/host/ohci-generic.c | 59
> >> +++++++++++++++++++++++++++++++++++++++--
> >> 1 file changed, 57 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/usb/host/ohci-generic.c
> >> b/drivers/usb/host/ohci-generic.c
> >> index f85738f..f76a1c2 100644
> >> --- a/drivers/usb/host/ohci-generic.c
> >> +++ b/drivers/usb/host/ohci-generic.c
> >> @@ -5,27 +5,83 @@
> >> */
> >>
> >> #include <common.h>
> >> +#include <clk.h>
> >> #include <dm.h>
> >> #include "ohci.h"
> >>
> >> +#include <dm/ofnode.h>
> >> +
> >> #if !defined(CONFIG_USB_OHCI_NEW)
> >> # error "Generic OHCI driver requires CONFIG_USB_OHCI_NEW"
> >> #endif
> >>
> >> struct generic_ohci {
> >> ohci_t ohci;
> >> + struct clk *clocks;
> >> + int clock_count;
> >> };
> >>
> >> static int ohci_usb_probe(struct udevice *dev)
> >> {
> >> struct ohci_regs *regs = (struct ohci_regs *)devfdt_get_addr(dev);
> >> + struct generic_ohci *priv = dev_get_priv(dev);
> >> + int i, err, ret, clock_nb;
> >> +
> >> + err = 0;
> >> + priv->clock_count = 0;
> >> + clock_nb = ofnode_count_phandle_with_args(dev_ofnode(dev), "clocks",
> >> + "#clock-cells");
> >> + if (clock_nb > 0) {
> >> + priv->clocks = devm_kmalloc(dev, sizeof(struct clk) * clock_nb,
> >> + GFP_KERNEL);
> >> + if (!priv->clocks) {
> >> + error("Can't allocate resource\n");
> >> + return -ENOMEM;
> >> + }
> >> +
> >> + for (i = 0; i < clock_nb; i++) {
> >> + err = clk_get_by_index(dev, i, &priv->clocks[i]);
> >> + if (err < 0)
> >> + break;
> >> +
> >> + priv->clock_count++;
> >> +
> >> + if (clk_enable(&priv->clocks[i])) {
> >> + error("failed to enable clock %d\n", i);
> >> + clk_free(&priv->clocks[i]);
> >> + goto clk_err;
> >> + }
> >> + clk_free(&priv->clocks[i]);
> >>
> > You free the freshly allocated clock right away and use it lateron?
>
> clk_free() didn't free clock resources, it's the opposite of
> clk_request(), see comments in include.clk.h
>
But as long as you are working with some resource (whether it's a
clock, a gpio, a 'reset' or whatever), you should keep it requested and
free it only after you relinquished using it.
Otherwise the object you are using may be destroyed underneath your
feet.
Lothar Waßmann
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