| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <CAOf5uwmpiOv_GED23hWDArcOvs6DpHNEy=OJ9vnKem1pg8jSgw@mail.gmail.com>
Date: Mon, 2 Dec 2013 10:51:08 +0100
From: Michael Trimarchi <michael@...rulasolutions.com>
To: Roger Quadros <rogerq@...com>
Cc: Lee Jones <lee.jones@...aro.org>, sameo@...ux.intel.com,
tomi.valkeinen@...com, Felipe Balbi <balbi@...com>,
Stefan Roese <sr@...x.de>, ljkenny.mailinglists@...il.com,
Linux OMAP Mailing List <linux-omap@...r.kernel.org>,
USB list <linux-usb@...r.kernel.org>,
linux-kernel@...r.kernel.org, stable@...r.kernel.org,
Benoit Cousson <bcousson@...libre.com>,
"tony@...mide.com" <tony@...mide.com>,
Paul Walmsley <paul@...an.com>
Subject: Re: [PATCH 1/1] mfd: omap-usb-host: Fix USB device detection problems
on OMAP4 Panda
Hi Roger
On Mon, Dec 2, 2013 at 10:39 AM, Roger Quadros <rogerq@...com> wrote:
> +Benoit, Tony, Paul.
>
> Hi Michael,
>
> On 11/30/2013 06:48 AM, Michael Trimarchi wrote:
>> Hi Roger
>>
>> On Fri, Nov 29, 2013 at 2:01 PM, Roger Quadros <rogerq@...com> wrote:
>>> With u-boot 2013.10, USB devices are sometimes not detected
>>> on OMAP4 Panda. To make us independent of what bootloader does
>>> with the USB Host module, we must RESET it to get it to a known
>>> good state. This patch Soft RESETs the USB Host module.
>>>
>>> Reported-by: Tomi Valkeinen <tomi.valkeinen@...com>
>>> Cc: <stable@...r.kernel.org> # 3.10+
>>> Signed-off-by: Roger Quadros <rogerq@...com>
>>> ---
>>> drivers/mfd/omap-usb-host.c | 115 +++++++++++++++++++++++++++++++++++++++++---
>>> 1 file changed, 109 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/mfd/omap-usb-host.c b/drivers/mfd/omap-usb-host.c
>>> index 142650f..d4bd464 100644
>>> --- a/drivers/mfd/omap-usb-host.c
>>> +++ b/drivers/mfd/omap-usb-host.c
>>> @@ -43,14 +43,18 @@
>>> /* UHH Register Set */
>>> #define OMAP_UHH_REVISION (0x00)
>>> #define OMAP_UHH_SYSCONFIG (0x10)
>>> -#define OMAP_UHH_SYSCONFIG_MIDLEMODE (1 << 12)
>>> +#define OMAP_UHH_SYSCONFIG_MIDLEMASK (3 << 12)
>>> +#define OMAP_UHH_SYSCONFIG_MIDLESHIFT (12)
>>> #define OMAP_UHH_SYSCONFIG_CACTIVITY (1 << 8)
>>> -#define OMAP_UHH_SYSCONFIG_SIDLEMODE (1 << 3)
>>> +#define OMAP_UHH_SYSCONFIG_SIDLEMASK (3 << 3)
>>> +#define OMAP_UHH_SYSCONFIG_SIDLESHIFT (3)
>>> #define OMAP_UHH_SYSCONFIG_ENAWAKEUP (1 << 2)
>>> #define OMAP_UHH_SYSCONFIG_SOFTRESET (1 << 1)
>>> #define OMAP_UHH_SYSCONFIG_AUTOIDLE (1 << 0)
>>>
>>> #define OMAP_UHH_SYSSTATUS (0x14)
>>> +#define OMAP_UHH_SYSSTATUS_RESETDONE (1 << 0)
>>> +
>>> #define OMAP_UHH_HOSTCONFIG (0x40)
>>> #define OMAP_UHH_HOSTCONFIG_ULPI_BYPASS (1 << 0)
>>> #define OMAP_UHH_HOSTCONFIG_ULPI_P1_BYPASS (1 << 0)
>>> @@ -66,10 +70,10 @@
>>> #define OMAP4_UHH_HOSTCONFIG_APP_START_CLK (1 << 31)
>>>
>>> /* OMAP4-specific defines */
>>> -#define OMAP4_UHH_SYSCONFIG_IDLEMODE_CLEAR (3 << 2)
>>> -#define OMAP4_UHH_SYSCONFIG_NOIDLE (1 << 2)
>>> -#define OMAP4_UHH_SYSCONFIG_STDBYMODE_CLEAR (3 << 4)
>>> -#define OMAP4_UHH_SYSCONFIG_NOSTDBY (1 << 4)
>>> +#define OMAP4_UHH_SYSCONFIG_MIDLEMASK (3 << 2)
>>> +#define OMAP4_UHH_SYSCONFIG_MIDLESHIFT (2)
>>> +#define OMAP4_UHH_SYSCONFIG_SIDLEMASK (3 << 4)
>>> +#define OMAP4_UHH_SYSCONFIG_SIDLESHIFT (4)
>>> #define OMAP4_UHH_SYSCONFIG_SOFTRESET (1 << 0)
>>>
>>> #define OMAP4_P1_MODE_CLEAR (3 << 16)
>>> @@ -81,6 +85,12 @@
>>>
>>> #define OMAP_UHH_DEBUG_CSR (0x44)
>>>
>>> +/* MIDLE modes */
>>> +#define OMAP_UHH_SYSCONFIG_MIDLE_NOSTANDBY (1)
>>> +
>>> +/* SIDLE modes */
>>> +#define OMAP_UHH_SYSCONFIG_SIDLE_NOIDLE (1)
>>> +
>>> /* Values of UHH_REVISION - Note: these are not given in the TRM */
>>> #define OMAP_USBHS_REV1 0x00000010 /* OMAP3 */
>>> #define OMAP_USBHS_REV2 0x50700100 /* OMAP4 */
>>> @@ -474,6 +484,97 @@ static unsigned omap_usbhs_rev2_hostconfig(struct usbhs_hcd_omap *omap,
>>> return reg;
>>> }
>>>
>>
>> I'm digging in the code but as I understand this should be done by
>> omap_hwmod and
>> i660 avoid reset of the ehci module. This is done by ocp_softreset?
>>
>
> It won't be done by omap_hwmod as we set HWMOD_INIT_NO_RESET flag in the hwmod data [1].
>
> Question is do we do it in the driver of leave it to hwmod?
>
> The other concern about i660 is in this comment [1]
>
I don't find any description of this errata for omap4. Is this errata valid?
My change was to remove the NO_INIT and add 2uS as you have done
> /*
> * During system oot; If the hwmod framework resets the module
> * the module will have smart idle settings; which can lead to deadlock
> * (above Errata Id:i660); so, dont reset the module during boot;
> * Use HWMOD_INIT_NO_RESET.
> */
>
> But if you look at the errata document [2], Advisory 1.108, it doesn't say that we can't be in smart-idle, but
> only that we should put the module in force-idle, before cutting the module's functional clock. It also states
> that the only way to recover from a lockup condition is to soft reset the module. So I'm not sure if the above comment
> in the code is really valid. What if the lockup happens in the bootloader? In that case we will have to reset the module in
> the kernel.
Michael
>
> Doing the reset in probe does solve a problem for now i.e. eliminates dependency on bootloader.
>
> [1] - http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c#n2024
> [2] - http://www.ti.com/litv/pdf/sprz318e
>
>>
>>> +static void omap_usbhs_rev1_reset(struct device *dev)
>>> +{
>>> + struct usbhs_hcd_omap *omap = dev_get_drvdata(dev);
>>> + u32 reg;
>>> + unsigned long timeout;
>>> +
>>> + reg = usbhs_read(omap->uhh_base, OMAP_UHH_SYSCONFIG);
>>> +
>>> + /* Soft Reset */
>>> + usbhs_write(omap->uhh_base, OMAP_UHH_SYSCONFIG,
>>> + reg | OMAP_UHH_SYSCONFIG_SOFTRESET);
>>> +
>>> + timeout = jiffies + msecs_to_jiffies(100);
>>> + while (!(usbhs_read(omap->uhh_base, OMAP_UHH_SYSSTATUS)
>>> + & OMAP_UHH_SYSSTATUS_RESETDONE)) {
>>> + cpu_relax();
>>> +
>>> + if (time_after(jiffies, timeout)) {
>>> + dev_err(dev, "Soft RESET operation timed out\n");
>>> + break;
>>> + }
>>> + }
>>> +
>>> + /* Set No-Standby */
>>> + reg &= ~OMAP_UHH_SYSCONFIG_MIDLEMASK;
>>> + reg |= OMAP_UHH_SYSCONFIG_MIDLE_NOSTANDBY
>>> + << OMAP_UHH_SYSCONFIG_MIDLESHIFT;
>>> +
>>> + /* Set No-Idle */
>>> + reg &= ~OMAP_UHH_SYSCONFIG_SIDLEMASK;
>>> + reg |= OMAP_UHH_SYSCONFIG_SIDLE_NOIDLE
>>> + << OMAP_UHH_SYSCONFIG_SIDLESHIFT;
>>> +
>>> + usbhs_write(omap->uhh_base, OMAP_UHH_SYSCONFIG, reg);
>>> +}
>>> +
>>> +static void omap_usbhs_rev2_reset(struct device *dev)
>>> +{
>>> + struct usbhs_hcd_omap *omap = dev_get_drvdata(dev);
>>> + u32 reg;
>>> + unsigned long timeout;
>>> +
>>> + reg = usbhs_read(omap->uhh_base, OMAP_UHH_SYSCONFIG);
>>> +
>>> + /* Soft Reset */
>>> + usbhs_write(omap->uhh_base, OMAP_UHH_SYSCONFIG,
>>> + reg | OMAP4_UHH_SYSCONFIG_SOFTRESET);
>>> +
>>> + /* OMAP4: Need to wait before SYSCONFIG can be accessed */
>>> + udelay(2);
>>
>> is this the srst_udelay?
>
> It was supposed to be, but it doesn't seem to be necessary for the UHH module. So I'll get rid of that.
>
Ok
> cheers,
> -roger
>
Michael
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists