Re: [PATCH 4/8] scsi: ufs: Make .get_hba_mac() optional

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

+ Can

On Wed, Jun 19, 2024 at 12:43:29PM +0530, Manivannan Sadhasivam wrote:
> On Mon, Jun 17, 2024 at 02:07:43PM -0700, Bart Van Assche wrote:
> > UFSHCI controllers that are compliant with the UFSHCI 4.0 standard report
> > the maximum number of supported commands in the controller capabilities
> > register. Use that value if .get_hba_mac == NULL.
> > 
> > Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> > ---
> >  drivers/ufs/core/ufs-mcq.c | 12 +++++++-----
> >  include/ufs/ufshcd.h       |  4 +++-
> >  include/ufs/ufshci.h       |  2 +-
> >  3 files changed, 11 insertions(+), 7 deletions(-)
> > 
> > diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
> > index 0482c7a1e419..d6f966f4abef 100644
> > --- a/drivers/ufs/core/ufs-mcq.c
> > +++ b/drivers/ufs/core/ufs-mcq.c
> > @@ -138,7 +138,6 @@ EXPORT_SYMBOL_GPL(ufshcd_mcq_queue_cfg_addr);
> >   *
> >   * MAC - Max. Active Command of the Host Controller (HC)
> >   * HC wouldn't send more than this commands to the device.
> > - * It is mandatory to implement get_hba_mac() to enable MCQ mode.
> >   * Calculates and adjusts the queue depth based on the depth
> >   * supported by the HC and ufs device.
> >   */
> > @@ -146,10 +145,13 @@ int ufshcd_mcq_decide_queue_depth(struct ufs_hba *hba)
> >  {
> >  	int mac = -EOPNOTSUPP;
> >  
> > -	if (!hba->vops || !hba->vops->get_hba_mac)
> > -		goto err;
> > -
> > -	mac = hba->vops->get_hba_mac(hba);
> > +	if (!hba->vops || !hba->vops->get_hba_mac) {
> > +		hba->capabilities =
> > +			ufshcd_readl(hba, REG_CONTROLLER_CAPABILITIES);
> > +		mac = (hba->capabilities & MASK_TRANSFER_REQUESTS_SLOTS) + 1;
> > +	} else {
> > +		mac = hba->vops->get_hba_mac(hba);
> > +	}
> >  	if (mac < 0)
> >  		goto err;
> >  
> > diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
> > index d4d63507d090..d32637d267f3 100644
> > --- a/include/ufs/ufshcd.h
> > +++ b/include/ufs/ufshcd.h
> > @@ -325,7 +325,9 @@ struct ufs_pwr_mode_info {
> >   * @event_notify: called to notify important events
> >   * @reinit_notify: called to notify reinit of UFSHCD during max gear switch
> >   * @mcq_config_resource: called to configure MCQ platform resources
> > - * @get_hba_mac: called to get vendor specific mac value, mandatory for mcq mode
> > + * @get_hba_mac: reports maximum number of outstanding commands supported by
> > + *	the controller. Should be implemented for UFSHCI 4.0 or later
> > + *	controllers that are not compliant with the UFSHCI 4.0 specification.
> >   * @op_runtime_config: called to config Operation and runtime regs Pointers
> >   * @get_outstanding_cqs: called to get outstanding completion queues
> >   * @config_esi: called to config Event Specific Interrupt
> > diff --git a/include/ufs/ufshci.h b/include/ufs/ufshci.h
> > index c50f92bf2e1d..899077bba2d2 100644
> > --- a/include/ufs/ufshci.h
> > +++ b/include/ufs/ufshci.h
> > @@ -67,7 +67,7 @@ enum {
> >  
> >  /* Controller capability masks */
> >  enum {
> > -	MASK_TRANSFER_REQUESTS_SLOTS		= 0x0000001F,
> > +	MASK_TRANSFER_REQUESTS_SLOTS		= 0x000000FF,
> 
> This should be a separate fix that comes before this patch. But I believe this
> came up during MCQ review as well and I don't remember what was the reply from
> Can. 0x1F is the mask for SDB mode and 0xFF is the mask for MCQ mode.
> 
> Can, can you comment more?
> 

Oops. Can is not CCed. Added now.

- Mani


> - Mani
> 
> -- 
> மணிவண்ணன் சதாசிவம்

-- 
மணிவண்ணன் சதாசிவம்