On 5/6/2013 11:07 AM, Seungwon Jeon wrote:
> Link start-up requires long time with multiphase handshakes
> between UFS host and device. This affects driver's probe time.
> This patch let link start-up run asynchronously. Link start-up
> will be executed at the end of prove separately.
> Along with this change, the following is worked.
>
> Defined completion time of uic command to avoid a permanent wait.
We have seen a kernel crash when the timeout happens in our internal
testing. This is basically because the the UIC_CMD_TIMEOUT of 500msec is
less for our platform. We see UIC_COMMAND_COMPL interrupt after this
timeout and since uic_cmd is freed we see a kernel crash.
[ 6.026094] ufshcd 0000:01:00.0: link startup: error code -110
[ 6.030886] ufshcd 0000:01:00.0: link startup failed -110
...
[ 6.487288] BUG: spinlock bad magic on CPU#0, swapper/0/0
[ 6.491683] Unable to handle kernel paging request at virtual address
6000012b
...
[ 7.625270] [<c07c3718>] (spin_dump+0x4c/0x88) from [<c02ab9d8>]
(do_raw_spin_lock+0x20/0x154)
[ 7.633877] [<c02ab9d8>] (do_raw_spin_lock+0x20/0x154) from
[<c07ccba4>] (_raw_spin_lock_irqsave+0x28/0x30)
[ 7.643583] [<c07ccba4>] (_raw_spin_lock_irqsave+0x28/0x30) from
[<c00a3c98>] (complete+0x1c/0x58)
[ 7.652525] [<c00a3c98>] (complete+0x1c/0x58) from [<c03d10c4>]
(ufshcd_intr+0x1a8/0x498)
[ 7.660705] [<c03d10c4>] (ufshcd_intr+0x1a8/0x498) from [<c00cff48>]
(handle_irq_event_percpu+0xb0/0x290)
[ 7.670227] [<c00cff48>] (handle_irq_event_percpu+0xb0/0x290) from
[<c00d0164>] (handle_irq_event+0x3c/0x5c)
[ 7.680054] [<c00d0164>] (handle_irq_event+0x3c/0x5c) from
[<c00d2c50>] (handle_fasteoi_irq+0xdc/0x148)
[ 7.689424] [<c00d2c50>] (handle_fasteoi_irq+0xdc/0x148) from
[<c00cf7ac>] (generic_handle_irq+0x30/0x44)
[ 7.698977] [<c00cf7ac>] (generic_handle_irq+0x30/0x44) from
[<c000ee40>] (handle_IRQ+0x7c/0xc0)
[ 7.707736] [<c000ee40>] (handle_IRQ+0x7c/0xc0) from [<c0008620>]
(gic_handle_irq+0x94/0x110)
[ 7.716252] [<c0008620>] (gic_handle_irq+0x94/0x110) from
[<c07ccec0>] (__irq_svc+0x40/0x70)
Following would fix this. Please check. Also, we need to increase the
timeout to say 5 secs to avoid such races.
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index ecbae40..ae22a8e 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -485,6 +485,7 @@ static int
ufshcd_wait_for_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
{
int ret;
+ unsigned long flags;
if (wait_for_completion_timeout(&uic_cmd->done,
msecs_to_jiffies(UIC_CMD_TIMEOUT)))
@@ -492,6 +493,10 @@ ufshcd_wait_for_uic_cmd(struct ufs_hba *hba, struct
uic_command *uic_cmd)
else
ret = -ETIMEDOUT;
+ spin_lock_irqsave(hba->host->host_lock, flags);
+ hba->active_uic_cmd = NULL;
+ spin_unlock_irqrestore(hba->host->host_lock, flags);
+
return ret;
}
@@ -1842,7 +1847,7 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba,
struct ufshcd_lrb *lrbp)
*/
static void ufshcd_uic_cmd_compl(struct ufs_hba *hba, u32 intr_status)
{
- if (intr_status & UIC_COMMAND_COMPL) {
+ if (hba->active_uic_cmd && (intr_status & UIC_COMMAND_COMPL)) {
hba->active_uic_cmd->argument2 |=
ufshcd_get_uic_cmd_result(hba);
hba->active_uic_cmd->argument3 =
> Added mutex to guarantee of uic command at a time.
> Adapted some sequence of controller initialization after link statup
> according to HCI standard.
>
> Signed-off-by: Seungwon Jeon <tgih....@samsung.com>
> Signed-off-by: Sujit Reddy Thumma <sthu...@codeaurora.org>
> ---
> drivers/scsi/ufs/ufshcd.c | 287
> ++++++++++++++++++++++++++++++---------------
> drivers/scsi/ufs/ufshcd.h | 10 +-
> 2 files changed, 200 insertions(+), 97 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index e04c74e..118f104 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -33,11 +33,15 @@
> * this program.
> */
>
> +#include <linux/async.h>
> +
> #include "ufshcd.h"
>
> #define UFSHCD_ENABLE_INTRS (UTP_TRANSFER_REQ_COMPL |\
> UTP_TASK_REQ_COMPL |\
> UFSHCD_ERROR_MASK)
> +/* UIC command timeout, unit: ms */
> +#define UIC_CMD_TIMEOUT 500
>
> enum {
> UFSHCD_MAX_CHANNEL = 0,
> @@ -401,24 +405,115 @@ static inline void ufshcd_hba_capabilities(struct
> ufs_hba *hba)
> }
>
> /**
> - * ufshcd_send_uic_command - Send UIC commands to unipro layers
> + * ufshcd_ready_for_uic_cmd - Check if controller is ready
> + * to accept UIC commands
> * @hba: per adapter instance
> - * @uic_command: UIC command
> + * Return true on success, else false
> + */
> +static inline bool ufshcd_ready_for_uic_cmd(struct ufs_hba *hba)
> +{
> + if (ufshcd_readl(hba, REG_CONTROLLER_STATUS) & UIC_COMMAND_READY)
> + return true;
> + else
> + return false;
> +}
> +
> +/**
> + * ufshcd_dispatch_uic_cmd - Dispatch UIC commands to unipro layers
> + * @hba: per adapter instance
> + * @uic_cmd: UIC command
> + *
> + * Mutex must be held.
> */
> static inline void
> -ufshcd_send_uic_command(struct ufs_hba *hba, struct uic_command *uic_cmnd)
> +ufshcd_dispatch_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
> {
> + hba->active_uic_cmd = uic_cmd;
> +
> /* Write Args */
> - ufshcd_writel(hba, uic_cmnd->argument1, REG_UIC_COMMAND_ARG_1);
> - ufshcd_writel(hba, uic_cmnd->argument2, REG_UIC_COMMAND_ARG_2);
> - ufshcd_writel(hba, uic_cmnd->argument3, REG_UIC_COMMAND_ARG_3);
> + ufshcd_writel(hba, uic_cmd->argument1, REG_UIC_COMMAND_ARG_1);
> + ufshcd_writel(hba, uic_cmd->argument2, REG_UIC_COMMAND_ARG_2);
> + ufshcd_writel(hba, uic_cmd->argument3, REG_UIC_COMMAND_ARG_3);
>
> /* Write UIC Cmd */
> - ufshcd_writel(hba, uic_cmnd->command & COMMAND_OPCODE_MASK,
> + ufshcd_writel(hba, uic_cmd->command & COMMAND_OPCODE_MASK,
> REG_UIC_COMMAND);
> }
>
> /**
> + * ufshcd_wait_for_uic_cmd - Wait complectioin of UIC command
> + * @hba: per adapter instance
> + * @uic_command: UIC command
> + *
> + * Must be called with mutex held.
> + * Returns 0 only if success.
> + */
> +static int
> +ufshcd_wait_for_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
> +{
> + int ret;
> +
> + if (wait_for_completion_timeout(&uic_cmd->done,
> + msecs_to_jiffies(UIC_CMD_TIMEOUT)))
> + ret = uic_cmd->argument2 & MASK_UIC_COMMAND_RESULT;
> + else
> + ret = -ETIMEDOUT;
> +
> + return ret;
> +}
> +
> +/**
> + * __ufshcd_send_uic_cmd - Send UIC commands and retrieve the result
> + * @hba: per adapter instance
> + * @uic_cmd: UIC command
> + *
> + * Identical to ufshcd_send_uic_cmd() expect mutex. Must be called
> + * with mutex held.
> + * Returns 0 only if success.
> + */
> +static int
> +__ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
> +{
> + int ret;
> + unsigned long flags;
> +
> + if (!ufshcd_ready_for_uic_cmd(hba)) {
> + dev_err(hba->dev,
> + "Controller not ready to accept UIC commands\n");
> + return -EIO;
> + }
> +
> + init_completion(&uic_cmd->done);
> +
> + spin_lock_irqsave(hba->host->host_lock, flags);
> + ufshcd_dispatch_uic_cmd(hba, uic_cmd);
> + spin_unlock_irqrestore(hba->host->host_lock, flags);
> +
> + ret = ufshcd_wait_for_uic_cmd(hba, uic_cmd);
> +
> + return ret;
> +}
> +
> +/**
> + * ufshcd_send_uic_cmd - Send UIC commands and retrieve the result
> + * @hba: per adapter instance
> + * @uic_cmd: UIC command
> + *
> + * Returns 0 only if success.
> + */
> +static int
> +ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
> +{
> + int ret;
> +
> + mutex_lock(&hba->uic_cmd_mutex);
> + ret = __ufshcd_send_uic_cmd(hba, uic_cmd);
> + mutex_unlock(&hba->uic_cmd_mutex);
> +
> + return ret;
> +}
> +
> +/**
> * ufshcd_map_sg - Map scatter-gather list to prdt
> * @lrbp - pointer to local reference block
> *
> @@ -962,34 +1057,16 @@ static void ufshcd_host_memory_configure(struct
> ufs_hba *hba)
> */
> static int ufshcd_dme_link_startup(struct ufs_hba *hba)
> {
> - struct uic_command *uic_cmd;
> - unsigned long flags;
> + struct uic_command uic_cmd = {0};
> + int ret;
>
> - /* check if controller is ready to accept UIC commands */
> - if ((ufshcd_readl(hba, REG_CONTROLLER_STATUS) &
> - UIC_COMMAND_READY) == 0x0) {
> - dev_err(hba->dev,
> - "Controller not ready"
> - " to accept UIC commands\n");
> - return -EIO;
> - }
> -
> - spin_lock_irqsave(hba->host->host_lock, flags);
> + uic_cmd.command = UIC_CMD_DME_LINK_STARTUP;
>
> - /* form UIC command */
> - uic_cmd = &hba->active_uic_cmd;
> - uic_cmd->command = UIC_CMD_DME_LINK_STARTUP;
> - uic_cmd->argument1 = 0;
> - uic_cmd->argument2 = 0;
> - uic_cmd->argument3 = 0;
> -
> - /* enable UIC related interrupts */
> - ufshcd_enable_intr(hba, UIC_COMMAND_COMPL);
> -
> - /* sending UIC commands to controller */
> - ufshcd_send_uic_command(hba, uic_cmd);
> - spin_unlock_irqrestore(hba->host->host_lock, flags);
> - return 0;
> + ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
> + if (ret)
> + dev_err(hba->dev,
> + "link startup: error code %d\n", ret);
> + return ret;
> }
>
> /**
> @@ -998,9 +1075,10 @@ static int ufshcd_dme_link_startup(struct ufs_hba *hba)
> *
> * To bring UFS host controller to operational state,
> * 1. Check if device is present
> - * 2. Configure run-stop-registers
> - * 3. Enable required interrupts
> - * 4. Configure interrupt aggregation
> + * 2. Enable required interrupts
> + * 3. Configure interrupt aggregation
> + * 4. Program UTRL and UTMRL base addres
> + * 5. Configure run-stop-registers
> *
> * Returns 0 on success, non-zero value on failure
> */
> @@ -1017,6 +1095,22 @@ static int ufshcd_make_hba_operational(struct ufs_hba
> *hba)
> goto out;
> }
>
> + /* Enable required interrupts */
> + ufshcd_enable_intr(hba, UFSHCD_ENABLE_INTRS);
> +
> + /* Configure interrupt aggregation */
> + ufshcd_config_int_aggr(hba, INT_AGGR_CONFIG);
> +
> + /* Configure UTRL and UTMRL base address registers */
> + ufshcd_writel(hba, lower_32_bits(hba->utrdl_dma_addr),
> + REG_UTP_TRANSFER_REQ_LIST_BASE_L);
> + ufshcd_writel(hba, upper_32_bits(hba->utrdl_dma_addr),
> + REG_UTP_TRANSFER_REQ_LIST_BASE_H);
> + ufshcd_writel(hba, lower_32_bits(hba->utmrdl_dma_addr),
> + REG_UTP_TASK_REQ_LIST_BASE_L);
> + ufshcd_writel(hba, upper_32_bits(hba->utmrdl_dma_addr),
> + REG_UTP_TASK_REQ_LIST_BASE_H);
> +
> /*
> * UCRDY, UTMRLDY and UTRLRDY bits must be 1
> * DEI, HEI bits must be 0
> @@ -1030,17 +1124,11 @@ static int ufshcd_make_hba_operational(struct ufs_hba
> *hba)
> goto out;
> }
>
> - /* Enable required interrupts */
> - ufshcd_enable_intr(hba, UFSHCD_ENABLE_INTRS);
> -
> - /* Configure interrupt aggregation */
> - ufshcd_config_int_aggr(hba, INT_AGGR_CONFIG);
> -
> if (hba->ufshcd_state == UFSHCD_STATE_RESET)
> scsi_unblock_requests(hba->host);
>
> hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
> - scsi_scan_host(hba->host);
> +
> out:
> return err;
> }
> @@ -1109,34 +1197,29 @@ static int ufshcd_hba_enable(struct ufs_hba *hba)
> }
>
> /**
> - * ufshcd_initialize_hba - start the initialization process
> + * ufshcd_link_startup - Initialize unipro link startup
> * @hba: per adapter instance
> *
> - * 1. Enable the controller via ufshcd_hba_enable.
> - * 2. Program the Transfer Request List Address with the starting address of
> - * UTRDL.
> - * 3. Program the Task Management Request List Address with starting address
> - * of UTMRDL.
> - *
> - * Returns 0 on success, non-zero value on failure.
> + * Returns 0 for success, non-zero in case of failure
> */
> -static int ufshcd_initialize_hba(struct ufs_hba *hba)
> +static int ufshcd_link_startup(struct ufs_hba *hba)
> {
> - if (ufshcd_hba_enable(hba))
> - return -EIO;
> + int ret;
>
> - /* Configure UTRL and UTMRL base address registers */
> - ufshcd_writel(hba, lower_32_bits(hba->utrdl_dma_addr),
> - REG_UTP_TRANSFER_REQ_LIST_BASE_L);
> - ufshcd_writel(hba, upper_32_bits(hba->utrdl_dma_addr),
> - REG_UTP_TRANSFER_REQ_LIST_BASE_H);
> - ufshcd_writel(hba, lower_32_bits(hba->utmrdl_dma_addr),
> - REG_UTP_TASK_REQ_LIST_BASE_L);
> - ufshcd_writel(hba, upper_32_bits(hba->utmrdl_dma_addr),
> - REG_UTP_TASK_REQ_LIST_BASE_H);
> + /* enable UIC related interrupts */
> + ufshcd_enable_intr(hba, UIC_COMMAND_COMPL);
> +
> + ret = ufshcd_dme_link_startup(hba);
> + if (ret)
> + goto out;
>
> - /* Initialize unipro link startup procedure */
> - return ufshcd_dme_link_startup(hba);
> + ret = ufshcd_make_hba_operational(hba);
> + if (ret)
> + goto out;
> +
> +out:
> + dev_err(hba->dev, "link startup failed %d\n", ret);
> + return ret;
> }
>
> /**
> @@ -1176,12 +1259,19 @@ static int ufshcd_do_reset(struct ufs_hba *hba)
> hba->outstanding_reqs = 0;
> hba->outstanding_tasks = 0;
>
> - /* start the initialization process */
> - if (ufshcd_initialize_hba(hba)) {
> + /* Host controller enable */
> + if (ufshcd_hba_enable(hba)) {
> dev_err(hba->dev,
> "Reset: Controller initialization failed\n");
> return FAILED;
> }
> +
> + if (ufshcd_link_startup(hba)) {
> + dev_err(hba->dev,
> + "Reset: Link start-up failed\n");
> + return FAILED;
> + }
> +
> return SUCCESS;
> }
>
> @@ -1434,6 +1524,17 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct
> ufshcd_lrb *lrbp)
> }
>
> /**
> + * ufshcd_uic_cmd_compl - handle completion of uic command
> + * @hba: per adapter instance
> + */
> +static void ufshcd_uic_cmd_compl(struct ufs_hba *hba)
> +{
> + hba->active_uic_cmd->argument2 |=
> + ufshcd_get_uic_cmd_result(hba);
> + complete(&hba->active_uic_cmd->done);
> +}
> +
> +/**
> * ufshcd_transfer_req_compl - handle SCSI and query command completion
> * @hba: per adapter instance
> */
> @@ -1473,28 +1574,6 @@ static void ufshcd_transfer_req_compl(struct ufs_hba
> *hba)
> }
>
> /**
> - * ufshcd_uic_cc_handler - handle UIC command completion
> - * @work: pointer to a work queue structure
> - *
> - * Returns 0 on success, non-zero value on failure
> - */
> -static void ufshcd_uic_cc_handler (struct work_struct *work)
> -{
> - struct ufs_hba *hba;
> -
> - hba = container_of(work, struct ufs_hba, uic_workq);
> -
> - if ((hba->active_uic_cmd.command == UIC_CMD_DME_LINK_STARTUP) &&
> - !(ufshcd_get_uic_cmd_result(hba))) {
> -
> - if (ufshcd_make_hba_operational(hba))
> - dev_err(hba->dev,
> - "cc: hba not operational state\n");
> - return;
> - }
> -}
> -
> -/**
> * ufshcd_fatal_err_handler - handle fatal errors
> * @hba: per adapter instance
> */
> @@ -1555,7 +1634,7 @@ static void ufshcd_sl_intr(struct ufs_hba *hba, u32
> intr_status)
> ufshcd_err_handler(hba);
>
> if (intr_status & UIC_COMMAND_COMPL)
> - schedule_work(&hba->uic_workq);
> + ufshcd_uic_cmd_compl(hba);
>
> if (intr_status & UTP_TASK_REQ_COMPL)
> ufshcd_tmc_handler(hba);
> @@ -1778,6 +1857,21 @@ out:
> return err;
> }
>
> +/**
> + * ufshcd_async_scan - asynchronous execution for link startup
> + * @data: data pointer to pass to this function
> + * @cookie: cookie data
> + */
> +static void ufshcd_async_scan(void *data, async_cookie_t cookie)
> +{
> + struct ufs_hba *hba = (struct ufs_hba *)data;
> + int ret;
> +
> + ret = ufshcd_link_startup(hba);
> + if (!ret)
> + scsi_scan_host(hba->host);
> +}
> +
> static struct scsi_host_template ufshcd_driver_template = {
> .module = THIS_MODULE,
> .name = UFSHCD,
> @@ -1939,12 +2033,14 @@ int ufshcd_init(struct device *dev, struct ufs_hba
> **hba_handle,
> init_waitqueue_head(&hba->ufshcd_tm_wait_queue);
>
> /* Initialize work queues */
> - INIT_WORK(&hba->uic_workq, ufshcd_uic_cc_handler);
> INIT_WORK(&hba->feh_workq, ufshcd_fatal_err_handler);
>
> /* Initialize mutex for query requests */
> mutex_init(&hba->query.lock_ufs_query);
>
> + /* Initialize UIC command mutex */
> + mutex_init(&hba->uic_cmd_mutex);
> +
> /* IRQ registration */
> err = request_irq(irq, ufshcd_intr, IRQF_SHARED, UFSHCD, hba);
> if (err) {
> @@ -1965,14 +2061,17 @@ int ufshcd_init(struct device *dev, struct ufs_hba
> **hba_handle,
> goto out_free_irq;
> }
>
> - /* Initialization routine */
> - err = ufshcd_initialize_hba(hba);
> + /* Host controller enable */
> + err = ufshcd_hba_enable(hba);
> if (err) {
> - dev_err(hba->dev, "Initialization failed\n");
> + dev_err(hba->dev, "Host controller enable failed\n");
> goto out_remove_scsi_host;
> }
> +
> *hba_handle = hba;
>
> + async_schedule(ufshcd_async_scan, hba);
> +
> return 0;
>
> out_remove_scsi_host:
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index d98e046..974bd07 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -51,6 +51,7 @@
> #include <linux/bitops.h>
> #include <linux/pm_runtime.h>
> #include <linux/clk.h>
> +#include <linux/completion.h>
>
> #include <asm/irq.h>
> #include <asm/byteorder.h>
> @@ -76,6 +77,7 @@
> * @argument3: UIC command argument 3
> * @cmd_active: Indicate if UIC command is outstanding
> * @result: UIC command result
> + * @done: UIC command completion
> */
> struct uic_command {
> u32 command;
> @@ -84,6 +86,7 @@ struct uic_command {
> u32 argument3;
> int cmd_active;
> int result;
> + struct completion done;
> };
>
> /**
> @@ -150,11 +153,11 @@ struct ufs_query {
> * @ufs_version: UFS Version to which controller complies
> * @irq: Irq number of the controller
> * @active_uic_cmd: handle of active UIC command
> + * @uic_cmd_mutex: mutex for uic command
> * @ufshcd_tm_wait_queue: wait queue for task management
> * @tm_condition: condition variable for task management
> * @ufshcd_state: UFSHCD states
> * @intr_mask: Interrupt Mask Bits
> - * @uic_workq: Work queue for UIC completion handling
> * @feh_workq: Work queue for fatal controller error handling
> * @errors: HBA errors
> * @query: query request information
> @@ -186,7 +189,9 @@ struct ufs_hba {
> u32 ufs_version;
> unsigned int irq;
>
> - struct uic_command active_uic_cmd;
> + struct uic_command *active_uic_cmd;
> + struct mutex uic_cmd_mutex;
> +
> wait_queue_head_t ufshcd_tm_wait_queue;
> unsigned long tm_condition;
>
> @@ -194,7 +199,6 @@ struct ufs_hba {
> u32 intr_mask;
>
> /* Work Queues */
> - struct work_struct uic_workq;
> struct work_struct feh_workq;
>
> /* HBA Errors */
>
--
Regards,
Sujit
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