Re: [PATCH] scsi: megaraid: cleanup formatting of megaraid

[Tom Rix]

On 1/27/22 2:47 PM, Nick Desaulniers wrote:
> + Miguel (the clang-format maintainer), Joe (checkpatch maintainer)
> These criticisms are worth reviewing.
>
> On Thu, Jan 27, 2022 at 2:38 PM Finn Thain <fthain@xxxxxxxxxxxxxx> wrote:
> > On Thu, 27 Jan 2022, trix@xxxxxxxxxx wrote:
> >
> > > From: Tom Rix <trix@xxxxxxxxxx>
> > >
> > > checkpatch reports several hundred formatting errors. Run these files
> > > through clang-format and knock off some of them.
> > That method seems like a good recipe for endless churn unless checkpatch
> > and clang-format really agree about these style rules.
> >
> > Why use checkpatch to assess code style, if we could simply diff the
> > existing source with the output from clang-format... but it seems that
> > clang-format harms readability, makes indentation errors and uses
> > inconsistent style rules. Some examples:

Problems with clang-format should be fixed, I'll take a look.

I was reviewing this file for another issue and could not get past how 
horredously bad it was and really did not want to manually fix the 400+ 
formatting errors.  I will drop this patch and use the use these files 
to verify the .clang-format .

Tom

> > >   static unsigned short int max_sectors_per_io = MAX_SECTORS_PER_IO;
> > >   module_param(max_sectors_per_io, ushort, 0);
> > > -MODULE_PARM_DESC(max_sectors_per_io, "Maximum number of sectors per I/O request (default=MAX_SECTORS_PER_IO=128)");
> > > -
> > > +MODULE_PARM_DESC(
> > > +     max_sectors_per_io,
> > > +     "Maximum number of sectors per I/O request (default=MAX_SECTORS_PER_IO=128)");
> > >
> > >   static unsigned short int max_mbox_busy_wait = MBOX_BUSY_WAIT;
> > >   module_param(max_mbox_busy_wait, ushort, 0);
> > > -MODULE_PARM_DESC(max_mbox_busy_wait, "Maximum wait for mailbox in microseconds if busy (default=MBOX_BUSY_WAIT=10)");
> > > +MODULE_PARM_DESC(
> > > +     max_mbox_busy_wait,
> > > +     "Maximum wait for mailbox in microseconds if busy (default=MBOX_BUSY_WAIT=10)");
> > This code is longer for no real improvement.
> >
> > >   /*
> > >    * The File Operations structure for the serial/ioctl interface of the driver
> > >    */
> > >   static const struct file_operations megadev_fops = {
> > > -     .owner          = THIS_MODULE,
> > > -     .unlocked_ioctl = megadev_unlocked_ioctl,
> > > -     .open           = megadev_open,
> > > -     .llseek         = noop_llseek,
> > > +     .owner = THIS_MODULE,
> > > +     .unlocked_ioctl = megadev_unlocked_ioctl,
> > > +     .open = megadev_open,
> > > +     .llseek = noop_llseek,
> > >   };
> > >
> > >   /*
> > Readability loss.
> >
> > > -             prod_info_dma_handle = dma_map_single(&adapter->dev->dev,
> > > -                                                   (void *)&adapter->product_info,
> > > -                                                   sizeof(mega_product_info),
> > > -                                                   DMA_FROM_DEVICE);
> > > +             prod_info_dma_handle = dma_map_single(
> > > +                     &adapter->dev->dev, (void *)&adapter->product_info,
> > > +                     sizeof(mega_product_info), DMA_FROM_DEVICE);
> > Note the orphaned first parameter and odd indentation.
> >
> > >   static DEF_SCSI_QCMD(megaraid_queue)
> > >
> > > -/**
> > > +     /**
> > >    * mega_allocate_scb()
> > >    * @adapter: pointer to our soft state
> > >    * @cmd: scsi command from the mid-layer
> > Indentation error.
> >
> > > @@ -418,15 +409,14 @@ static DEF_SCSI_QCMD(megaraid_queue)
> > >    * Allocate a SCB structure. This is the central structure for controller
> > >    * commands.
> > >    */
> > > -static inline scb_t *
> > > -mega_allocate_scb(adapter_t *adapter, struct scsi_cmnd *cmd)
> > > +     static inline scb_t *mega_allocate_scb(adapter_t *adapter,
> > > +                                            struct scsi_cmnd *cmd)
> > >   {
> > >        struct list_head *head = &adapter->free_list;
> > Same.
> >
> > > @@ -586,26 +568,25 @@ mega_build_cmd(adapter_t *adapter, struct scsi_cmnd *cmd, int *busy)
> > >
> > >                ldrv_num = mega_get_ldrv_num(adapter, cmd, channel);
> > >
> > > -
> > >                max_ldrv_num = (adapter->flag & BOARD_40LD) ?
> > > -                     MAX_LOGICAL_DRIVES_40LD : MAX_LOGICAL_DRIVES_8LD;
> > > +                                    MAX_LOGICAL_DRIVES_40LD :
> > > +                                          MAX_LOGICAL_DRIVES_8LD;
> > Churn, if not readability loss. Note the indentation change here is
> > inconsistent with the indentation change noted above.
> >
> > >                         * 6-byte READ(0x08) or WRITE(0x0A) cdb
> > >                         */
> > > -                     if( cmd->cmd_len == 6 ) {
> > > -                             mbox->m_out.numsectors = (u32) cmd->cmnd[4];
> > > -                             mbox->m_out.lba =
> > > -                                     ((u32)cmd->cmnd[1] << 16) |
> > > -                                     ((u32)cmd->cmnd[2] << 8) |
> > > -                                     (u32)cmd->cmnd[3];
> > > +                     if (cmd->cmd_len == 6) {
> > > +                             mbox->m_out.numsectors = (u32)cmd->cmnd[4];
> > > +                             mbox->m_out.lba = ((u32)cmd->cmnd[1] << 16) |
> > > +                                               ((u32)cmd->cmnd[2] << 8) |
> > > +                                               (u32)cmd->cmnd[3];
> > >
> > >                                mbox->m_out.lba &= 0x1FFFFF;
> > Here, the orphaned term is moved up, next to the =. And yet,
> >
> > >                        /* Calculate Scatter-Gather info */
> > > -                     mbox->m_out.numsgelements = mega_build_sglist(adapter, scb,
> > > -                                     (u32 *)&mbox->m_out.xferaddr, &seg);
> > > +                     mbox->m_out.numsgelements =
> > > +                             mega_build_sglist(adapter, scb,
> > > +                                               (u32 *)&mbox->m_out.xferaddr,
> > > +                                               &seg);
> > >
> > >                        return scb;
> > ... here the first term is moved down and orphaned, which is another
> > inconsistency.