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Groups > linux.kernel > #1713549
| From | Kishon Vijay Abraham I <kishon@ti.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [RFC PATCH 1/7] mmc: sdhci: Add quirk to indicate no CRC stripping in MMC_RSP_136 |
| Date | 2017-08-17 07:30 +0200 |
| Message-ID | <uflxv-i7-7@gated-at.bofh.it> (permalink) |
| References | <ubSLn-2uu-5@gated-at.bofh.it> <ubSLo-2uu-15@gated-at.bofh.it> <ueECd-6Oz-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Hi Adrian,
On Tuesday 15 August 2017 12:57 PM, Adrian Hunter wrote:
> On 07/08/17 19:01, Kishon Vijay Abraham I wrote:
>> TI's implementation of sdhci controller used in DRA7 SoC's doesn't
>> strip CRC in responses with length 136 bits. Add quirk to indicate
>> the controller does not strip CRC in MMC_RSP_136. If this quirk is
>> set sdhci library shouldn't shift the response present in
>> SDHCI_RESPONSE register.
>>
>> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
>> ---
>> drivers/mmc/host/sdhci.c | 27 +++++++++++++++++++--------
>> drivers/mmc/host/sdhci.h | 2 ++
>> 2 files changed, 21 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index ecd0d4350e8a..ece3751d2a25 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -1182,14 +1182,25 @@ static void sdhci_finish_command(struct sdhci_host *host)
>>
>> if (cmd->flags & MMC_RSP_PRESENT) {
>> if (cmd->flags & MMC_RSP_136) {
>> - /* CRC is stripped so we need to do some shifting. */
>> - for (i = 0;i < 4;i++) {
>> - cmd->resp[i] = sdhci_readl(host,
>> - SDHCI_RESPONSE + (3-i)*4) << 8;
>> - if (i != 3)
>> - cmd->resp[i] |=
>> - sdhci_readb(host,
>> - SDHCI_RESPONSE + (3-i)*4-1);
>> + if (!(host->quirks2 & SDHCI_QUIRK2_NO_CRC_STRIPPING)) {
>
> This is about the 136-bit response so let's put that in the quirk name. How about SDHCI_QUIRK2_RSP_136_HAS_CRC
Since omap seems to be the only platform that doesn't have CRC, I prefer adding
SDHCI_QUIRK2_RSP_136_NO_CRC. That way we can add the quirk only in sdhci-omap
instead of all the existing sdhci drivers.
>
>> + /*
>> + * CRC is stripped so we need to do some
>> + * shifting.
>> + */
>> + for (i = 0; i < 4; i++) {
>> + cmd->resp[i] =
>> + sdhci_readl(host, SDHCI_RESPONSE
>> + + (3 - i) * 4) << 8;
>> + if (i != 3)
>> + cmd->resp[i] |=
>> + sdhci_readb(host, SDHCI_RESPONSE
>> + + (3 - i) * 4 - 1);
>> + }
>> + } else {
>> + for (i = 0; i < 4; i++)
>> + cmd->resp[i] =
>> + sdhci_readl(host, SDHCI_RESPONSE +
>> + (3 - i) * 4);
>> }
>
> This is all very jammed up against the 80 column margin. Please make a new patch to separate it into a new function sdhci_read_rsp_136() and then another patch to add the quirk.
> i.e. completely untested!
Sure. Thanks for the patch.
Thanks
Kishon
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Re: [RFC PATCH 1/7] mmc: sdhci: Add quirk to indicate no CRC stripping in MMC_RSP_136 Adrian Hunter <adrian.hunter@intel.com> - 2017-08-15 09:40 +0200
Re: [RFC PATCH 1/7] mmc: sdhci: Add quirk to indicate no CRC stripping in MMC_RSP_136 Kishon Vijay Abraham I <kishon@ti.com> - 2017-08-17 07:30 +0200
Re: [RFC PATCH 1/7] mmc: sdhci: Add quirk to indicate no CRC stripping in MMC_RSP_136 Adrian Hunter <adrian.hunter@intel.com> - 2017-08-17 08:40 +0200
Re: [RFC PATCH 1/7] mmc: sdhci: Add quirk to indicate no CRC stripping in MMC_RSP_136 Kishon Vijay Abraham I <kishon@ti.com> - 2017-08-17 09:50 +0200
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