Messages in this thread | | | Subject | Re: PATCH: rtsx_pci driver - don't disable the rts5229 card reader on Intel NUC boxes | From | Chris Clayton <> | Date | Tue, 4 Aug 2020 09:50:45 +0100 |
| |
On 04/08/2020 09:08, 吳昊澄 Ricky wrote: >> -----Original Message----- >> From: gregkh@linuxfoundation.org [mailto:gregkh@linuxfoundation.org] >> Sent: Tuesday, August 04, 2020 3:49 PM >> To: 吳昊澄 Ricky >> Cc: Chris Clayton; LKML; rdunlap@infradead.org; philquadra@gmail.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.
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.
Chris >> greg k-h >> >> ------Please consider the environment before printing this e-mail.
| |