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charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org On 6/18/22 05:31, Serge Semin wrote: > On Thu, Jun 16, 2022 at 09:28:18AM +0900, Damien Le Moal wrote: >> On 2022/06/16 5:58, Serge Semin wrote: >>> On Tue, Jun 14, 2022 at 05:32:41PM +0900, Damien Le Moal wrote: >>>> On 6/10/22 17:17, Serge Semin wrote: >>>>> Currently not all of the Port-specific capabilities listed in the >>>> >>>> s/listed/are listed >>>> >>>>> PORT_CMD-enumeration. Let's extend that set with the Cold Presence >>>>> Detection and Mechanical Presence Switch attached to the Port flags [1] so >>>>> to closeup the set of the platform-specific port-capabilities flags. Note >>>>> these flags are supposed to be set by the platform firmware if there is >>>>> one. Alternatively as we are about to do they can be set by means of the >>>>> OF properties. >>>>> >>>>> While at it replace PORT_IRQ_DEV_ILCK with PORT_IRQ_DMPS and fix the >>>>> comment there. In accordance with [2] that IRQ flag is supposed to >>>>> indicate the state of the signal coming from the Mechanical Presence >>>>> Switch. >>>>> >>>>> [1] Serial ATA AHCI 1.3.1 Specification, p.27 >>>>> [2] Serial ATA AHCI 1.3.1 Specification, p.24, p.88 >>>>> >>>>> Signed-off-by: Serge Semin >>>>> Reviewed-by: Hannes Reinecke >>>>> >>>>> --- >>>>> >>>>> Changelog v4: >>>>> - Fix the DMPS macros name in the patch log. (@Sergei Shtylyov) >>>>> --- >>>>> drivers/ata/ahci.h | 7 ++++++- >>>>> 1 file changed, 6 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h >>>>> index 7d834deefeb9..f501531bd1b3 100644 >>>>> --- a/drivers/ata/ahci.h >>>>> +++ b/drivers/ata/ahci.h >>>>> @@ -138,7 +138,7 @@ enum { >>>>> PORT_IRQ_BAD_PMP = (1 << 23), /* incorrect port multiplier */ >>>>> >>>>> PORT_IRQ_PHYRDY = (1 << 22), /* PhyRdy changed */ >>>>> - PORT_IRQ_DEV_ILCK = (1 << 7), /* device interlock */ >>>>> + PORT_IRQ_DMPS = (1 << 7), /* mechanical presence status */ >>>>> PORT_IRQ_CONNECT = (1 << 6), /* port connect change status */ >>>>> PORT_IRQ_SG_DONE = (1 << 5), /* descriptor processed */ >>>>> PORT_IRQ_UNK_FIS = (1 << 4), /* unknown FIS rx'd */ >>>>> @@ -166,6 +166,8 @@ enum { >>>>> PORT_CMD_ATAPI = (1 << 24), /* Device is ATAPI */ >>>>> PORT_CMD_FBSCP = (1 << 22), /* FBS Capable Port */ >>>>> PORT_CMD_ESP = (1 << 21), /* External Sata Port */ >>>>> + PORT_CMD_CPD = (1 << 20), /* Cold Presence Detection */ >>>>> + PORT_CMD_MPSP = (1 << 19), /* Mechanical Presence Switch */ >>>>> PORT_CMD_HPCP = (1 << 18), /* HotPlug Capable Port */ >>>>> PORT_CMD_PMP = (1 << 17), /* PMP attached */ >>>>> PORT_CMD_LIST_ON = (1 << 15), /* cmd list DMA engine running */ >>>>> @@ -181,6 +183,9 @@ enum { >>>>> PORT_CMD_ICC_PARTIAL = (0x2 << 28), /* Put i/f in partial state */ >>>>> PORT_CMD_ICC_SLUMBER = (0x6 << 28), /* Put i/f in slumber state */ >>>>> >>>>> + PORT_CMD_CAP = PORT_CMD_HPCP | PORT_CMD_MPSP | >>>>> + PORT_CMD_CPD | PORT_CMD_ESP | PORT_CMD_FBSCP, >>>> >>> >>>> What is this one for ? A comment above it would be nice. >>> >>> Isn't it obviously inferrable from the definition and the item name? >> > >> I am guessing from the name. Am I guessing OK ? A comment would still be nice. >> Why just these bits ? There are more cap/support indicator bits in that port cmd >> bitfield. So why this particular set of bits ? What do they mean all together ? > > Normally the variable/constant name should be self-content (as the > kernel coding style doc states and what the common sense suggests). So > the reader could correctly guess its purpose/content/value. In this > case PORT_CMD_CAP - means PORT CMD capabilities mask. All of the > possible flags have been set in that mask. There are no more > capabilities in the PORT CMD register left undeclared. That's why the > name is selected the way it is and why I haven't added any comment in > here (what the kernel coding style says about the over-commenting the > code). Yes, I understood from the name what it is. What I do NOT understand is why all the feature bits are not there. Why this subset only ? A comment about that would be nice so that the reason for it is not lost. > >> >> Sure I can go and read the specs to figure it out. But again, a comment would >> avoid readers of the code to have to decrypt all that. > > If you still insist on having an additional comment. I can add > something like "/* PORT_CMD capabilities mask */". Are you ok with it? That does not help on its own. The macro name says that already. I would like a note about why only these features are selected. > > -Sergey > >> >>> >>> -Sergey >>> >>>> >>>>> + >>>>> /* PORT_FBS bits */ >>>>> PORT_FBS_DWE_OFFSET = 16, /* FBS device with error offset */ >>>>> PORT_FBS_ADO_OFFSET = 12, /* FBS active dev optimization offset */ >>>> >>>> >>>> -- >>>> Damien Le Moal >>>> Western Digital Research >> >> >> -- >> Damien Le Moal >> Western Digital Research -- Damien Le Moal Western Digital Research