linux-kernel - RE: PATCH: rtsx_pci driver - don't disable the rts5229 card reader on Intel NUC boxes

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Message-ID: <e1c295f28e3d4bdd8c78dfd3a5ed398c@realtek.com>
Date:   Wed, 5 Aug 2020 02:35:52 +0000
From:   吳昊澄 Ricky <ricky_wu@...ltek.com>
To:     Chris Clayton <chris2553@...glemail.com>,
        "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>
CC:     LKML <linux-kernel@...r.kernel.org>,
        "rdunlap@...radead.org" <rdunlap@...radead.org>,
        "philquadra@...il.com" <philquadra@...il.com>,
        "Arnd Bergmann" <arnd@...db.de>
Subject: RE: PATCH: rtsx_pci driver - don't disable the rts5229 card reader on Intel NUC boxes



> -----Original Message-----
> From: Chris Clayton [mailto:chris2553@...glemail.com]
> Sent: Tuesday, August 04, 2020 7:52 PM
> To: 吳昊澄 Ricky; gregkh@...uxfoundation.org
> Cc: LKML; rdunlap@...radead.org; philquadra@...il.com; Arnd Bergmann
> Subject: Re: PATCH: rtsx_pci driver - don't disable the rts5229 card reader on
> Intel NUC boxes
> 
> 
> 
> On 04/08/2020 11:46, 吳昊澄 Ricky wrote:
> >> -----Original Message-----
> >> From: Chris Clayton [mailto:chris2553@...glemail.com]
> >> Sent: Tuesday, August 04, 2020 4:51 PM
> >> To: 吳昊澄 Ricky; gregkh@...uxfoundation.org
> >> Cc: LKML; rdunlap@...radead.org; philquadra@...il.com; Arnd Bergmann
> >> Subject: Re: PATCH: rtsx_pci driver - don't disable the rts5229 card reader on
> >> Intel NUC boxes
> >>
> >>
> >>
> >> On 04/08/2020 09:08, 吳昊澄 Ricky wrote:
> >>>> -----Original Message-----
> >>>> From: gregkh@...uxfoundation.org [mailto:gregkh@...uxfoundation.org]
> >>>> Sent: Tuesday, August 04, 2020 3:49 PM
> >>>> To: 吳昊澄 Ricky
> >>>> Cc: Chris Clayton; LKML; rdunlap@...radead.org; philquadra@...il.com;
> >> Arnd
> >>>> Bergmann
> >>>> Subject: Re: PATCH: rtsx_pci driver - don't disable the rts5229 card reader
> on
> >>>> Intel NUC boxes
> >>>>
> >>>> On Tue, Aug 04, 2020 at 02:44:41AM +0000, 吳昊澄 Ricky wrote:
> >>>>> Hi Chris,
> >>>>>
> >>>>> rtsx_pci_write_register(pcr, FPDTL, OC_POWER_DOWN,
> >> OC_POWER_DOWN);
> >>>>> This register operation saved power under 1mA, so if do not care the 1mA
> >>>> power we can have a patch to remove it, make compatible with NUC6
> >>>>> We tested others our card reader that remove it, we did not see any side
> >> effect
> >>>>>
> >>>>> Hi Greg k-h,
> >>>>>
> >>>>> Do you have any comments?
> >>>>
> >>>> comments on what?  I don't know what you are responding to here, sorry.
> >>>>
> >>> Can we have a patch to kernel for NUC6? It may cause more power(1mA) but
> it
> >> will have more compatibility
> >>>
> >>
> >> Ricky,
> >>
> >> I don't understand why you want to completely remove the code that sets up
> the
> >> 1mA power saving. That code was there
> >> even before your patch (bede03a579b3b4a036003c4862cc1baa4ddc351f), so I
> >> assume it benefits some of the Realtek card
> >> readers. Before your patch however, rtsx_pci_init_ocp() was not called for the
> >> rts5229 reader, but the patch introduced
> >> an unconditional call to that function into rtsx_pci_init_hw(), which is run for
> the
> >> rts5229. That is what now disables
> >> the card reader.
> >>
> >> Now, I don't know whether other cards are affected, although I don't recall
> >> seeing any reported as I searched the kernel
> >> and ubuntu bugzillas for any analysis of the problem. I know this is not what
> the
> >> patch I sent does, but having thought
> >> about it more, seems to me that the simplest fix is to skip the new call to
> >> rtsx_pci_init_ocp() if the reader is an rts5229.
> >>
> >
> > Because we are thinking about if others our card reader that not belong A
> series(my ocp patch coverage) also on NUC6 platform maybe have the same
> problem...
> >
> 
> OK. What if we do make the new call but only for the card readers that are in the
> A series? Are they the ones that have
> PID_5nnn defines in include/linux/rtsx_pci.h? Or is there another simple way of
> identifying that a reader is a member of
> the A series?
> 
> I'm thinking of something like:
> static bool rtsx_pci_is_series_A(pcr)
> {
> 	unsigned short device = pcr->pci->device;
> 
> 	return device == PID524A || device == PID_5249 || device == PID_5250 ||
> device == PID_525A
> 			|| device == PID_525A || device == PID_5260 || device ==
> PID_5261;
> }
> 
> then in rtsx_pci_init_hw() change the unconditional call to:
> 
> 	if rtsx_pci_is_series_A(pcr)
> 		rtsx_pci_init_ocp();
> 
> Does that seem OK?
> 
Previously, I want to remove
else {
		/* OC power down */
		rtsx_pci_write_register(pcr, FPDCTL, OC_POWER_DOWN,
			OC_POWER_DOWN);
}
Because in our A-series card Reader we already assigned option->ocp_en to 1 in self init_params() , this is an easy way to fix this problem

> >> If you agree, I can prepare a patch and send it to you. Whatever the solution is,
> it
> >> will also be needed in the stable
> >> kernels later than 5.0.
> >>
> >
> > OK, I agree your opinion, for now can only patch rts5229 first make NUC6 user
> can work well
> >
> > Thank you
> >
> >> Chris
> >>>> greg k-h
> >>>>
> >>>> ------Please consider the environment before printing this e-mail.