[U-Boot] [PATCH v2 1/2] usb: ehci: exynos: Fix multiple FDT decode

[Simon Glass]

On Tue, Mar 5, 2013 at 5:40 AM, Vivek Gautam <gautamvivek1987 at gmail.com> wrote:
> Hi,
>
>
> On Thu, Feb 14, 2013 at 10:22 AM, Simon Glass <sjg at chromium.org> wrote:
>> Hi,
>>
>> On Tue, Feb 12, 2013 at 10:26 PM, Vivek Gautam <gautam.vivek at samsung.com> wrote:
>>> With current FDT support driver tries to parse device node
>>> twice in ehci_hcd_init() and ehci_hcd_stop(), which shouldn't
>>> happen ideally.
>>> Making provision to store data in a global structure and thereby
>>> passing its pointer when needed.
>>>
>>> Signed-off-by: Vivek Gautam <gautam.vivek at samsung.com>
>>
>> Nice patch.
>>
> Really sorry for the delay in responding.

No problem, we all have other things to do :-)

>
>>> ---
>>>
>>> This patch comes up as a fix for earlier problem of multiple FDT
>>> decode. Actually no 'v1' present for this patch.
>>>
>>>  drivers/usb/host/ehci-exynos.c |   40 +++++++++++-----------------------------
>>>  1 files changed, 11 insertions(+), 29 deletions(-)
>>>
>>> diff --git a/drivers/usb/host/ehci-exynos.c b/drivers/usb/host/ehci-exynos.c
>>> index 3ca4c5c..68f12fc 100644
>>> --- a/drivers/usb/host/ehci-exynos.c
>>> +++ b/drivers/usb/host/ehci-exynos.c
>>> @@ -42,9 +42,11 @@ DECLARE_GLOBAL_DATA_PTR;
>>>   */
>>>  struct exynos_ehci {
>>>         struct exynos_usb_phy *usb;
>>> -       unsigned int *hcd;
>>> +       unsigned int hcd;
>>
>> I think this should be a pointer. Perhaps a (struct ehci_hccr *?
>>
>
> Isn't it better to maintain it as unsigned int ?
> Since later when fdtdec_get_addr() is used, which returns u32 or u64,
> we can easily check against FDT_ADDR_T_NONE.
> ehci_hcd_init() can later typecast it to (struct ehci_hccr *) when needed.

How about having a local variable in your decode routine like:

fdt_addr_t addr;

addr = fdtdec_get_addr()...
if (addr == FDT_ADDR_NONE) {
   debug(...)
   return -1;
}
exynos->hcd = (struct ... *)addr;

I think this is better than holding a value that is the wrong type,
and casting it throughout your driver. Best to get the
casting/checking done at init time,

>
>>>  };
>>>
>>> +static struct exynos_ehci exynos;
>>> +
>>>  static int exynos_usb_parse_dt(const void *blob, struct exynos_ehci *exynos)
>>>  {
>>>         unsigned int node;
>>> @@ -59,8 +61,8 @@ static int exynos_usb_parse_dt(const void *blob, struct exynos_ehci *exynos)
>>>         /*
>>>          * Get the base address for EHCI controller from the device node
>>>          */
>>> -       exynos->hcd = (unsigned int *)fdtdec_get_addr(blob, node, "reg");
>>> -       if (exynos->hcd == NULL) {
>>> +       exynos->hcd = fdtdec_get_addr(blob, node, "reg");
>>> +       if (exynos->hcd < 0) {
>>
>> You need to check for FDT_ADDR_NONE here.
>>
> Sure.
>
>>>                 debug("Can't get the EHCI register address\n");
>>>                 return -ENXIO;
>>>         }
>>> @@ -144,20 +146,13 @@ static void reset_usb_phy(struct exynos_usb_phy *usb)
>>>   */
>>>  int ehci_hcd_init(int index, struct ehci_hccr **hccr, struct ehci_hcor **hcor)
>>>  {
>>> -       struct exynos_ehci *exynos = NULL;
>>> -
>>> -       exynos = (struct exynos_ehci *)
>>> -                       kzalloc(sizeof(struct exynos_ehci), GFP_KERNEL);
>>> -       if (!exynos) {
>>> -               debug("failed to allocate exynos ehci context\n");
>>> -               return -ENOMEM;
>>> -       }
>>> +       struct exynos_ehci *ctx = &exynos;
>>>
>>> -       exynos_usb_parse_dt(gd->fdt_blob, exynos);
>>> +       exynos_usb_parse_dt(gd->fdt_blob, ctx);
>>>
>>> -       setup_usb_phy(exynos->usb);
>>> +       setup_usb_phy(ctx->usb);
>>>
>>> -       *hccr = (struct ehci_hccr *)(exynos->hcd);
>>> +       *hccr = (struct ehci_hccr *)(ctx->hcd);
>>>         *hcor = (struct ehci_hcor *)((uint32_t) *hccr
>>>                                 + HC_LENGTH(ehci_readl(&(*hccr)->cr_capbase)));
>>>
>>> @@ -165,8 +160,6 @@ int ehci_hcd_init(int index, struct ehci_hccr **hccr, struct ehci_hcor **hcor)
>>>                 (uint32_t)*hccr, (uint32_t)*hcor,
>>>                 (uint32_t)HC_LENGTH(ehci_readl(&(*hccr)->cr_capbase)));
>>>
>>> -       kfree(exynos);
>>> -
>>>         return 0;
>>>  }
>>>
>>> @@ -176,20 +169,9 @@ int ehci_hcd_init(int index, struct ehci_hccr **hccr, struct ehci_hcor **hcor)
>>>   */
>>>  int ehci_hcd_stop(int index)
>>>  {
>>> -       struct exynos_ehci *exynos = NULL;
>>> -
>>> -       exynos = (struct exynos_ehci *)
>>> -                       kzalloc(sizeof(struct exynos_ehci), GFP_KERNEL);
>>> -       if (!exynos) {
>>> -               debug("failed to allocate exynos ehci context\n");
>>> -               return -ENOMEM;
>>> -       }
>>> -
>>> -       exynos_usb_parse_dt(gd->fdt_blob, exynos);
>>> -
>>> -       reset_usb_phy(exynos->usb);
>>> +       struct exynos_ehci *ctx = &exynos;
>>>
>>> -       kfree(exynos);
>>> +       reset_usb_phy(ctx->usb);
>>>
>>>         return 0;
>>>  }
>>> --
>>> 1.7.6.5
>>>
>>
>
> --
> Thanks & Regards
> Vivek

Regards,
Simon