On 5/15/23 20:33, Kiwoong Kim wrote:
v1 -> v2: replace usleep_range with udelay
because it's a sleepable period.
With auto hibern8 enabled, UIC could be working
for a while to process a hibern8 operation and HCI
reports UIC not ready for a short term through HCS.UCRDY.
And UFS driver can't recognize the operation.
UFSHCI spec specifies UCRDY like this:
whether the host controller is ready to process UIC COMMAND
The 'ready' could be seen as many different meanings. If the meaning
includes not processing any request from HCI, processing a hibern8
operation can be 'not ready'. In this situation, the driver needs to
wait until the operations is completed.
Signed-off-by: Kiwoong Kim <kwmad.kim@xxxxxxxxxxx>
---
drivers/ufs/core/ufshcd.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 9434328..5f6819a 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -2365,7 +2365,18 @@ static inline int ufshcd_hba_capabilities(struct ufs_hba *hba)
*/
static inline bool ufshcd_ready_for_uic_cmd(struct ufs_hba *hba)
{
- return ufshcd_readl(hba, REG_CONTROLLER_STATUS) & UIC_COMMAND_READY;
+ ktime_t timeout = ktime_add_ms(ktime_get(), UIC_CMD_TIMEOUT);
+ u32 val = 0;
+
+ do {
+ val = ufshcd_readl(hba, REG_CONTROLLER_STATUS) &
+ UIC_COMMAND_READY;
+ if (val)
+ break;
+ udelay(500);
+ } while (ktime_before(ktime_get(), timeout));
+
+ return val ? true : false;
}
Sleeping during up to 500 ms while holding a spin lock is not acceptable.
Has it been considered to modify the UFS core such that the host_lock is
not held around calls of the above function, e.g. via the (untested) patch
below?
Thanks,
Bart.
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 9736b2b4120e..394283b04d7c 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -2416,7 +2416,6 @@ __ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd,
bool completion)
{
lockdep_assert_held(&hba->uic_cmd_mutex);
- lockdep_assert_held(hba->host->host_lock);
if (!ufshcd_ready_for_uic_cmd(hba)) {
dev_err(hba->dev,
@@ -2452,9 +2451,7 @@ int ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
mutex_lock(&hba->uic_cmd_mutex);
ufshcd_add_delay_before_dme_cmd(hba);
- spin_lock_irqsave(hba->host->host_lock, flags);
ret = __ufshcd_send_uic_cmd(hba, uic_cmd, true);
- spin_unlock_irqrestore(hba->host->host_lock, flags);
if (!ret)
ret = ufshcd_wait_for_uic_cmd(hba, uic_cmd);
@@ -4122,8 +4119,8 @@ static int ufshcd_uic_pwr_ctrl(struct ufs_hba *hba, struct uic_command *cmd)
wmb();
reenable_intr = true;
}
- ret = __ufshcd_send_uic_cmd(hba, cmd, false);
spin_unlock_irqrestore(hba->host->host_lock, flags);
+ ret = __ufshcd_send_uic_cmd(hba, cmd, false);
if (ret) {
dev_err(hba->dev,
"pwr ctrl cmd 0x%x with mode 0x%x uic error %d\n",
