> -----Original Message----- > From: Adrian Hunter [mailto:adrian.hunter@xxxxxxxxx] > Sent: Friday, February 23, 2018 1:04 PM > To: Manish Narani <MNARANI@xxxxxxxxxx>; michal.simek@xxxxxxxxxx; > ulf.hansson@xxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux- > mmc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > devicetree@xxxxxxxxxxxxxxx; mark.rutland@xxxxxxx; robh+dt@xxxxxxxxxx > Cc: Anirudha Sarangi <anirudh@xxxxxxxxxx>; Srinivas Goud > <sgoud@xxxxxxxxxx> > Subject: Re: [RFC PATCH] mmc: sdhci-of-arasan: Add auto tuning support for > ZynqMP Platform > > On 23/02/18 09:29, Manish Narani wrote: > > > > > >> -----Original Message----- > >> From: Adrian Hunter [mailto:adrian.hunter@xxxxxxxxx] > >> Sent: Thursday, February 22, 2018 1:50 PM > >> To: Manish Narani <MNARANI@xxxxxxxxxx>; michal.simek@xxxxxxxxxx; > >> ulf.hansson@xxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux- > >> mmc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > >> devicetree@xxxxxxxxxxxxxxx; mark.rutland@xxxxxxx; > robh+dt@xxxxxxxxxx > >> Cc: Anirudha Sarangi <anirudh@xxxxxxxxxx>; Srinivas Goud > >> <sgoud@xxxxxxxxxx> > >> Subject: Re: [RFC PATCH] mmc: sdhci-of-arasan: Add auto tuning > >> support for ZynqMP Platform > >> > >> On 21/02/18 17:00, Manish Narani wrote: > >>> Hi Adrian, > >>> > >>>> -----Original Message----- > >>>> From: Manish Narani > >>>> Sent: Wednesday, February 21, 2018 11:39 AM > >>>> To: Adrian Hunter <adrian.hunter@xxxxxxxxx>; > >>>> michal.simek@xxxxxxxxxx; ulf.hansson@xxxxxxxxxx; > >>>> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux- mmc@xxxxxxxxxxxxxxx; > >>>> linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; > >>>> mark.rutland@xxxxxxx; > >> robh+dt@xxxxxxxxxx > >>>> Cc: Anirudha Sarangi <anirudh@xxxxxxxxxx>; Srinivas Goud > >>>> <sgoud@xxxxxxxxxx> > >>>> Subject: RE: [RFC PATCH] mmc: sdhci-of-arasan: Add auto tuning > >>>> support for ZynqMP Platform > >>>> > >>>> Hi Adrian, > >>>> > >>>> > >>>>> -----Original Message----- > >>>>> From: Adrian Hunter [mailto:adrian.hunter@xxxxxxxxx] > >>>>> Sent: Friday, February 16, 2018 7:37 PM > >>>>> To: Manish Narani <MNARANI@xxxxxxxxxx>; > michal.simek@xxxxxxxxxx; > >>>>> ulf.hansson@xxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > >>>>> linux- mmc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > >>>>> devicetree@xxxxxxxxxxxxxxx; mark.rutland@xxxxxxx; > >> robh+dt@xxxxxxxxxx > >>>>> Cc: Anirudha Sarangi <anirudh@xxxxxxxxxx>; Srinivas Goud > >>>>> <sgoud@xxxxxxxxxx>; Manish Narani <MNARANI@xxxxxxxxxx> > >>>>> Subject: Re: [RFC PATCH] mmc: sdhci-of-arasan: Add auto tuning > >>>>> support for ZynqMP Platform > >>>>> > >>>>> On 30/01/18 20:14, Manish Narani wrote: > >>>>>> This patch adds support of SD auto tuning for ZynqMP platform. > >>>>>> Auto tuning sequence sends tuning block to card when operating in > >>>>>> UHS-1 modes. This resets the DLL and sends CMD19/CMD21 as a part > >>>>>> of the auto tuning process. Once the auto tuning process gets > >>>>>> completed, reset the DLL to load the newly obtained SDHC tuned tap > value. > >>>>> > >>>>> How is this different from: > >>>>> 1. reset the dll > >>>>> 2. call sdhci_execute_tuning > >>>>> 3. reset the dll > >>>>> > >>> Below is my take on your above comments: > >>> - 'Reset the dll' is a platform specific call inside > >>> 'arasan_zynqmp_execute_tuning' which is implemented in > >>> sdhci-of-arasan.c > >>> - 'arasan_zynqmp_execute_tuning' is called from > 'sdhci_execute_tuning' > >>> as a platform_execute_tuning routine > >>> - So to keep 'DLL reset' routine called from sdhci-of-arasan.c, I > >>> have implemented the execute_tuning in sdhci-of-arasan.c > >> > >> I meant something like: > >> > >> if (of_device_is_compatible(pdev->dev.of_node, "xlnx,zynqmp- > >> 8.9a")) > >> host->mmc_host_ops.execute_tuning = > arasan_zynqmp_execute_tuning; > >> > > This will need the removal of 'const' from 'static const struct > mmc_host_ops sdhci_ops = {}' in sdhci.c file. Please confirm. > > No, it is not const. You are not looking at the right place. i.e. > > $ grep mmc_host_ops drivers/mmc/host/sdhci.h > struct mmc_host_ops mmc_host_ops; /* MMC host ops */ > [Manish] This looks fair. I got your point. I will send another patch for the same. > > > > Thanks, > > Manish > >> > >> static int arasan_zynqmp_execute_tuning(struct mmc_host *mmc, u32 > >> opcode) { > >> struct sdhci_host *host = mmc_priv(mmc); > >> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); > >> struct sdhci_arasan_data *sdhci_arasan = > >> sdhci_pltfm_priv(pltfm_host); > >> int err; > >> > >> arasan_zynqmp_dll_reset(host, sdhci_arasan->device_id); > >> > >> err = sdhci_execute_tuning(mmc, opcode); > >> if (err) > >> return err; > >> > >> arasan_zynqmp_dll_reset(host, sdhci_arasan->device_id); > >> > >> return 0; > >> } > >> > >>> > >>> Alternative way (Please review): > >>> - Define a host->quirk2 bit (SDHCI_QUIRK2_DLL_RESET_NEEDED) in > >>> sdhci-of-arasan.c indicating DLL reset needed while tuning operation > >>> - Call 'dll reset' routine before and after __sdhci_execute_tuning() > >>> in sdhci.c when a host->quirk2 bit (SDHCI_QUIRK2_DLL_RESET_NEEDED) > >>> is set > >> > >> We should try to avoid quirks. ��.n��������+%������w��{.n�����{��i��)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
