mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-30 06:10:56 +00:00
scsi: ufs: core: Perform read back after disabling interrupts
Currently, interrupts are cleared and disabled prior to registering the
interrupt. An mb() is used to complete the clear/disable writes before the
interrupt is registered.
mb() ensures that the write completes, but completion doesn't mean that it
isn't stored in a buffer somewhere. The recommendation for ensuring these
bits have taken effect on the device is to perform a read back to force it
to make it all the way to the device. This is documented in device-io.rst
and a talk by Will Deacon on this can be seen over here:
https://youtu.be/i6DayghhA8Q?si=MiyxB5cKJXSaoc01&t=1678
Let's do that to ensure these bits hit the device. Because the mb()'s
purpose wasn't to add extra ordering (on top of the ordering guaranteed by
writel()/readl()), it can safely be removed.
Fixes: 199ef13cac
("scsi: ufs: avoid spurious UFS host controller interrupts")
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Can Guo <quic_cang@quicinc.com>
Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
Link: https://lore.kernel.org/r/20240329-ufs-reset-ensure-effect-before-delay-v5-8-181252004586@redhat.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
parent
408e28086f
commit
e4a6288771
1 changed files with 1 additions and 1 deletions
|
@ -10616,7 +10616,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
|
|||
* Make sure that UFS interrupts are disabled and any pending interrupt
|
||||
* status is cleared before registering UFS interrupt handler.
|
||||
*/
|
||||
mb();
|
||||
ufshcd_readl(hba, REG_INTERRUPT_ENABLE);
|
||||
|
||||
/* IRQ registration */
|
||||
err = devm_request_irq(dev, irq, ufshcd_intr, IRQF_SHARED, UFSHCD, hba);
|
||||
|
|
Loading…
Reference in a new issue