Hello,
On 2015-10-06 01:27, Felipe Balbi wrote:
John Youn <John.Youn@xxxxxxxxxxxx> writes:
Hi,
On 10/2/2015 12:45 AM, Marek Szyprowski wrote:
DWC2 module on some platforms needs three additional hardware
resources: phy controller, clock and power supply. All of them must be
enabled/activated to properly initialize and operate. This was initially
handled in s3c-hsotg driver, which has been converted to 'gadget' part
of dwc2 driver. Unfortunately, not all of this code got moved to common
platform code, what resulted in accessing DWC2 registers without
enabling low-level hardware resources. This fails for example on Exynos
SoCs. This patch moves all the code for managing those resources to
common platform.c file and provides convenient wrappers for controlling
them.
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
Changelog:
v4:
- fixed broken conditional compilation and adjusted comments in dwc2_hsotg
structure documentation
v3:
- rebased onto latest 'testing/next' from Felipe Balbi (includes
s3c_hsotg -> dwc2 rename)
v2:
- moved setting of ll_hw_enabled flag to enable/disable functions,
as suggested by John Youn
- moved setting of phy width to dwc2_lowlevel_init function
---
drivers/usb/dwc2/core.h | 24 +++--
drivers/usb/dwc2/gadget.c | 193 ++++--------------------------------
drivers/usb/dwc2/platform.c | 234 +++++++++++++++++++++++++++++++++++++-------
3 files changed, 228 insertions(+), 223 deletions(-)
Hi Marek,
I still see lockdep warnings.
Any ideas about these?
[ 1618.179611] ======================================================
[ 1618.179612] [ INFO: possible circular locking dependency detected ]
[ 1618.179613] 4.3.0-rc3-snps-00125-g744fd93 #28 Not tainted
[ 1618.179614] -------------------------------------------------------
[ 1618.179615] modprobe/2658 is trying to acquire lock:
[ 1618.179616] (&hsotg->init_mutex){+.+.+.}, at: [<ffffffffc043aa3c>] dwc2_hsotg_udc_start+0x5c/0x200 [dwc2]
[ 1618.179622]
[ 1618.179622] but task is already holding lock:
[ 1618.179623] (udc_lock){+.+.+.}, at: [<ffffffffc0374b8a>] usb_gadget_probe_driver+0x3a/0xd0 [udc_core]
[ 1618.179627]
[ 1618.179627] which lock already depends on the new lock.
[ 1618.179627]
[ 1618.179628]
[ 1618.179628] the existing dependency chain (in reverse order) is:
[ 1618.179629]
[ 1618.179629] -> #1 (udc_lock){+.+.+.}:
[ 1618.179631] [<ffffffff810da56d>] lock_acquire+0xdd/0x1f0
[ 1618.179635] [<ffffffff818658a6>] mutex_lock_nested+0x76/0x3e0
[ 1618.179638] [<ffffffffc0374da7>] usb_add_gadget_udc_release+0x187/0x240 [udc_core]
[ 1618.179640] [<ffffffffc0374e70>] usb_add_gadget_udc+0x10/0x20 [udc_core]
[ 1618.179642] [<ffffffffc043b30c>] dwc2_gadget_init+0x47c/0x580 [dwc2]
[ 1618.179645] [<ffffffffc042d2f2>] dwc2_driver_probe+0x422/0x4b0 [dwc2]
[ 1618.179648] [<ffffffff8153fe94>] platform_drv_probe+0x34/0x90
[ 1618.179650] [<ffffffff8153db54>] driver_probe_device+0x224/0x480
[ 1618.179652] [<ffffffff8153deb1>] __device_attach_driver+0x71/0xa0
[ 1618.179654] [<ffffffff8153b78d>] bus_for_each_drv+0x5d/0x90
[ 1618.179655] [<ffffffff8153d83f>] __device_attach+0xbf/0x140
[ 1618.179657] [<ffffffff8153df23>] device_initial_probe+0x13/0x20
[ 1618.179658] [<ffffffff8153cb03>] bus_probe_device+0xa3/0xb0
[ 1618.179660] [<ffffffff8153a76d>] device_add+0x40d/0x690
[ 1618.179661] [<ffffffff8153fb81>] platform_device_add+0x111/0x270
[ 1618.179663] [<ffffffffc0394128>] dwc2_pci_probe+0xe8/0x1d2 [dwc2_pci]
[ 1618.179665] [<ffffffff81446085>] local_pci_probe+0x45/0xa0
[ 1618.179668] [<ffffffff81447451>] pci_device_probe+0xe1/0x130
[ 1618.179669] [<ffffffff8153db54>] driver_probe_device+0x224/0x480
[ 1618.179671] [<ffffffff8153de38>] __driver_attach+0x88/0x90
[ 1618.179672] [<ffffffff8153b6d6>] bus_for_each_dev+0x66/0xa0
[ 1618.179674] [<ffffffff8153d31e>] driver_attach+0x1e/0x20
[ 1618.179675] [<ffffffff8153ce8e>] bus_add_driver+0x1ee/0x280
[ 1618.179677] [<ffffffff8153e930>] driver_register+0x60/0xe0
[ 1618.179678] [<ffffffff81445a60>] __pci_register_driver+0x60/0x70
[ 1618.179680] [<ffffffffc000601e>] 0xffffffffc000601e
[ 1618.179681] [<ffffffff81002123>] do_one_initcall+0xb3/0x200
[ 1618.179684] [<ffffffff811a8a41>] do_init_module+0x5f/0x1e7
[ 1618.179687] [<ffffffff81120e48>] load_module+0x21a8/0x2840
[ 1618.179689] [<ffffffff8112170a>] SyS_finit_module+0x9a/0xc0
[ 1618.179691] [<ffffffff81869c36>] entry_SYSCALL_64_fastpath+0x16/0x7a
[ 1618.179693]
[ 1618.179693] -> #0 (&hsotg->init_mutex){+.+.+.}:
[ 1618.179695] [<ffffffff810d97f5>] __lock_acquire+0x1d35/0x1db0
[ 1618.179697] [<ffffffff810da56d>] lock_acquire+0xdd/0x1f0
[ 1618.179698] [<ffffffff818658a6>] mutex_lock_nested+0x76/0x3e0
[ 1618.179700] [<ffffffffc043aa3c>] dwc2_hsotg_udc_start+0x5c/0x200 [dwc2]
[ 1618.179703] [<ffffffffc0374a34>] udc_bind_to_driver+0xa4/0x100 [udc_core]
[ 1618.179705] [<ffffffffc0374bca>] usb_gadget_probe_driver+0x7a/0xd0 [udc_core]
[ 1618.179707] [<ffffffffc059a674>] usb_composite_probe+0xa4/0xc0 [libcomposite]
[ 1618.179709] [<ffffffffc0474010>] msg_init+0x10/0x1000 [g_mass_storage]
[ 1618.179711] [<ffffffff81002123>] do_one_initcall+0xb3/0x200
[ 1618.179713] [<ffffffff811a8a41>] do_init_module+0x5f/0x1e7
[ 1618.179714] [<ffffffff81120e48>] load_module+0x21a8/0x2840
[ 1618.179716] [<ffffffff8112170a>] SyS_finit_module+0x9a/0xc0
[ 1618.179717] [<ffffffff81869c36>] entry_SYSCALL_64_fastpath+0x16/0x7a
[ 1618.179719]
[ 1618.179719] other info that might help us debug this:
[ 1618.179719]
[ 1618.179720] Possible unsafe locking scenario:
[ 1618.179720]
[ 1618.179721] CPU0 CPU1
[ 1618.179722] ---- ----
[ 1618.179722] lock(udc_lock);
[ 1618.179723] lock(&hsotg->init_mutex);
It seems like init_mutex is completely unnecessary in this driver. In
fact, why are you trying to hold a mutex while inside a spinlock ?
init_mutex is a leftover from the time, when s3c-hsotg driver didn't
implement
proper pull up/down control and emulated it by enabling disabling phy.
It can
be removed now. btw, the possible lockup pointed by John is an
interaction of
two mutexes, not a case of taking mutex under a spinlock.
I will send an updated patch in a few minutes.
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
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