There are several benefits for doing like this: - hc_driver can be customized for each hcd - Other hcd hc_driver's initialization will not affect current one. We run out NULL pointer dereference problem when one hcd is started by module_init, and the other is started by otg thread at SMP platform. The reason for this problem is ehci_init_driver will do memory copy for current uniform hc_driver, and this memory copy will do memset (as 0) first, so when the first hcd is running usb_add_hcd, and the second hcd may clear the uniform hc_driver's space (at ehci_init_driver), then the first hcd will meet NULL pointer at the same time. See below two logs: LOG_1: ci_hdrc ci_hdrc.0: EHCI Host Controller ci_hdrc ci_hdrc.0: new USB bus registered, assigned bus number 1 ci_hdrc ci_hdrc.1: doesn't support gadget Unable to handle kernel NULL pointer dereference at virtual address 00000014 pgd = 80004000 [00000014] *pgd=00000000 Internal error: Oops: 805 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 108 Comm: kworker/u8:2 Not tainted 3.14.38-222193-g24b2734-dirty #25 Workqueue: ci_otg ci_otg_work task: d839ec00 ti: d8400000 task.ti: d8400000 PC is at ehci_run+0x4c/0x284 LR is at _raw_spin_unlock_irqrestore+0x28/0x54 pc : [<8041f9a0>] lr : [<8070ea84>] psr: 60000113 sp : d8401e30 ip : 00000000 fp : d8004400 r10: 00000001 r9 : 00000001 r8 : 00000000 r7 : 00000000 r6 : d8419940 r5 : 80dd24c0 r4 : d8419800 r3 : 8001d060 r2 : 00000000 r1 : 00000001 r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c53c7d Table: 1000404a DAC: 00000015 Process kworker/u8:2 (pid: 108, stack limit = 0xd8400238) Stack: (0xd8401e30 to 0xd8402000) 1e20: d87523c0 d8401e48 66667562 d8419800 1e40: 00000000 00000000 d8419800 00000000 00000000 00000000 d84198b0 8040fcdc 1e60: 00000000 80dd320c d8477610 d8419c00 d803d010 d8419800 00000000 00000000 1e80: d8004400 00000000 d8400008 80431494 80431374 d803d100 d803d010 d803d1ac 1ea0: 00000000 80432428 804323d4 d803d100 00000001 80435eb8 80e0d0bc d803d100 1ec0: 00000006 80436458 00000000 d803d100 80e92ec8 80436f44 d803d010 d803d100 1ee0: d83fde00 8043292c d8752710 d803d1f4 d803d010 8042ddfc 8042ddb8 d83f3b00 1f00: d803d1f4 80042b60 00000000 00000003 00000001 00000001 80054598 d83f3b00 1f20: d8004400 d83f3b18 d8004414 d8400000 80e3957b 00000089 d8004400 80043814 1f40: d839ec00 00000000 d83fcd80 d83f3b00 800436e4 00000000 00000000 00000000 1f60: 00000000 80048f34 00000000 00000000 00000000 d83f3b00 00000000 00000000 1f80: d8401f80 d8401f80 00000000 00000000 d8401f90 d8401f90 d8401fac d83fcd80 1fa0: 80048e68 00000000 00000000 8000e538 00000000 00000000 00000000 00000000 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 [<8041f9a0>] (ehci_run) from [<8040fcdc>] (usb_add_hcd+0x248/0x6e8) [<8040fcdc>] (usb_add_hcd) from [<80431494>] (host_start+0x120/0x2e4) [<80431494>] (host_start) from [<80432428>] (ci_otg_start_host+0x54/0xbc) [<80432428>] (ci_otg_start_host) from [<80435eb8>] (otg_set_protocol+0xa4/0xd0) [<80435eb8>] (otg_set_protocol) from [<80436458>] (otg_set_state+0x574/0xc58) [<80436458>] (otg_set_state) from [<80436f44>] (otg_statemachine+0x408/0x46c) [<80436f44>] (otg_statemachine) from [<8043292c>] (ci_otg_fsm_work+0x3c/0x190) [<8043292c>] (ci_otg_fsm_work) from [<8042ddfc>] (ci_otg_work+0x44/0x1c4) [<8042ddfc>] (ci_otg_work) from [<80042b60>] (process_one_work+0xf4/0x35c) [<80042b60>] (process_one_work) from [<80043814>] (worker_thread+0x130/0x3bc) [<80043814>] (worker_thread) from [<80048f34>] (kthread+0xcc/0xe4) [<80048f34>] (kthread) from [<8000e538>] (ret_from_fork+0x14/0x3c) Code: e5953018 e3530000 0a000000 e12fff33 (e5878014) LOG_2: ci_hdrc ci_hdrc.0: EHCI Host Controller ci_hdrc ci_hdrc.0: new USB bus registered, assigned bus number 1 ci_hdrc ci_hdrc.1: doesn't support gadget Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = 80004000 [00000000] *pgd=00000000 In Online 00:00ternal e Offline rror: Oops: 80000005 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 108 Comm: kworker/u8:2 Not tainted 3.14.38-02007-g24b2734-dirty #127 Workque Online 00:00ue: ci_o Offline tg ci_otg_work Online 00:00task: d8 Offline 39ec00 ti: d83ea000 task.ti: d83ea000 PC is at 0x0 LR is at usb_add_hcd+0x248/0x6e8 pc : [<00000000>] lr : [<8040f644>] psr: 60000113 sp : d83ebe60 ip : 00000000 fp : d8004400 r10: 00000001 r9 : 00000001 r8 : d85fd4b0 r7 : 00000000 r6 : 00000000 r5 : 00000000 r4 : d85fd400 r3 : 00000000 r2 : d85fd4f4 r1 : 80410178 r0 : d85fd400 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c53c7d Table: 1000404a DAC: 00000015 Process kworker/u8:2 (pid: 108, stack limit = 0xd83ea238) Stack: (0xd83ebe60 to 0xd83ec000) be60: 00000000 80dd920c d8654e10 d85fd800 d803e010 d85fd400 00000000 00000000 be80: d8004400 00000000 d83ea008 80430e34 80430d14 d803e100 d803e010 d803e1ac bea0: 00000000 80431dc8 80431d74 d803e100 00000001 80435858 80e130bc d803e100 bec0: 00000006 80435df8 00000000 d803e100 80e98ec8 804368e4 d803e010 d803e100 bee0: d86e8100 804322cc d86cf050 d803e1f4 d803e010 8042d79c 8042d758 d83cf900 bf00: d803e1f4 80042b78 00000000 00000003 00000001 00000001 800545e8 d83cf900 bf20: d8004400 d83cf918 d8004414 d83ea000 80e3f57b 00000089 d8004400 8004382c bf40: d839ec00 00000000 d8393780 d83cf900 800436fc 00000000 00000000 00000000 bf60: 00000000 80048f50 80e019f4 00000000 0000264c d83cf900 00000000 00000000 bf80: d83ebf80 d83ebf80 00000000 00000000 d83ebf90 d83ebf90 d83ebfac d8393780 bfa0: 80048e84 00000000 00000000 8000e538 00000000 00000000 00000000 00000000 bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 ee66e85d 133ebd03 [<804 Online 00:000f644>] Offline (usb_add_hcd) from [<80430e34>] (host_start+0x120/0x2e4) [<80430e34>] (host_start) from [<80431dc8>] (ci_otg_start_host+0x54/0xbc) [<80431dc8>] (ci_otg_start_host) from [<80435858>] (otg_set_protocol+0xa4/0xd0) [<80435858>] (otg_set_protocol) from [<80435df8>] (otg_set_state+0x574/0xc58) [<80435df8>] (otg_set_state) from [<804368e4>] (otg_statemachine+0x408/0x46c) [<804368e4>] (otg_statemachine) from [<804322cc>] (ci_otg_fsm_work+0x3c/0x190) [<804322cc>] (ci_otg_fsm_work) from [<8042d79c>] (ci_otg_work+0x44/0x1c4) [<8042d79c>] (ci_otg_work) from [<80042b78>] (process_one_work+0xf4/0x35c) [<80042b78>] (process_one_work) from [<8004382c>] (worker_thread+0x130/0x3bc) [<8004382c>] (worker_thread) from [<80048f50>] (kthread+0xcc/0xe4) [<80048f50>] (kthread) from [<8000e538>] (ret_from_fork+0x14/0x3c) Code: bad PC value Cc: Jun Li <jun.li@xxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx> --- drivers/usb/chipidea/host.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c index 30c09a8..32f0bc9 100644 --- a/drivers/usb/chipidea/host.c +++ b/drivers/usb/chipidea/host.c @@ -25,6 +25,7 @@ #include <linux/usb/hcd.h> #include <linux/usb/chipidea.h> #include <linux/regulator/consumer.h> +#include <linux/platform_device.h> #include "../host/ehci.h" @@ -32,7 +33,8 @@ #include "bits.h" #include "host.h" -static struct hc_driver __read_mostly ci_ehci_hc_driver; +#define MAX_CI_NUM 8 +static struct hc_driver __read_mostly ci_ehci_hc_driver[MAX_CI_NUM]; static int (*orig_bus_suspend)(struct usb_hcd *hcd); struct ehci_ci_priv { @@ -93,11 +95,13 @@ static int host_start(struct ci_hdrc *ci) struct ehci_hcd *ehci; struct ehci_ci_priv *priv; int ret; + struct platform_device *pdev = to_platform_device(ci->dev); if (usb_disabled()) return -ENODEV; - hcd = usb_create_hcd(&ci_ehci_hc_driver, ci->dev, dev_name(ci->dev)); + hcd = usb_create_hcd(&ci_ehci_hc_driver[pdev->id], + ci->dev, dev_name(ci->dev)); if (!hcd) return -ENOMEM; @@ -236,6 +240,8 @@ static int ci_ehci_bus_suspend(struct usb_hcd *hcd) int ci_hdrc_host_init(struct ci_hdrc *ci) { struct ci_role_driver *rdrv; + struct platform_device *pdev = to_platform_device(ci->dev); + struct hc_driver *ci_ehci_driver = &ci_ehci_hc_driver[pdev->id]; if (!hw_read(ci, CAP_DCCPARAMS, DCCPARAMS_HC)) return -ENXIO; @@ -250,9 +256,9 @@ int ci_hdrc_host_init(struct ci_hdrc *ci) rdrv->name = "host"; ci->roles[CI_ROLE_HOST] = rdrv; - ehci_init_driver(&ci_ehci_hc_driver, &ehci_ci_overrides); - orig_bus_suspend = ci_ehci_hc_driver.bus_suspend; - ci_ehci_hc_driver.bus_suspend = ci_ehci_bus_suspend; + ehci_init_driver(ci_ehci_driver, &ehci_ci_overrides); + orig_bus_suspend = ci_ehci_driver->bus_suspend; + ci_ehci_driver->bus_suspend = ci_ehci_bus_suspend; return 0; } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html