On 03/19/2018 11:53 AM, Geert Uytterhoeven wrote:
> Hi Marek,
>
> On Mon, Mar 19, 2018 at 10:53 AM, Marek Vasut <marek.vasut@xxxxxxxxx> wrote:
>> On 03/19/2018 09:38 AM, Simon Horman wrote:
>>> On Sun, Mar 18, 2018 at 11:52:52AM +0100, Marek Vasut wrote:
>>>> The data link active signal usually takes ~20 uSec to be asserted,
>>>> poll the bit more often to avoid useless delays in this function.
>>>>
>>>> Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxx>
>>>> Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
>>>> Cc: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>
>>>> Cc: Simon Horman <horms+renesas@xxxxxxxxxxxx>
>>>> Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
>>>> Cc: linux-renesas-soc@xxxxxxxxxxxxxxx
>>>
>>> Unless my eyes deceive me this seems to be quite a lot (100x) more often,
>>> but so be it.
>>
>> It's just a higher frequency to avoid slowdown when bringing the link up.
>
> No it isn't: you replaced a sleep by a delay, thus making it blocking.
For much shorter period of time.
> So this can spin for up to 50 ms (+ overhead)?
That's what it did before too , it used msleep and now it uses udelay.
>>>> --- a/drivers/pci/host/pcie-rcar.c
>>>> +++ b/drivers/pci/host/pcie-rcar.c
>>>> @@ -528,13 +528,13 @@ static void phy_write_reg(struct rcar_pcie *pcie,
>>>>
>>>> static int rcar_pcie_wait_for_dl(struct rcar_pcie *pcie)
>>>> {
>>>> - unsigned int timeout = 10;
>>>> + unsigned int timeout = 10000;
>>>>
>>>> while (timeout--) {
>>>> if ((rcar_pci_read_reg(pcie, PCIETSTR) & DATA_LINK_ACTIVE))
>>>> return 0;
>>>>
>>>> - msleep(5);
>>>> + udelay(5);
>>>> }
>>>>
>>>> return -ETIMEDOUT;
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
>
--
Best regards,
Marek Vasut
