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authorBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>2020-03-26 18:58:14 +0300
committerJens Axboe <axboe@kernel.dk>2020-03-26 19:28:19 +0300
commit9d3158f5cb11142d85c351fa0e0087ef95ac9cb8 (patch)
tree1bfd452012c17ea525acec6eb36c9fbd327adc14 /drivers/ata/libata-sata.c
parentab4117cf2470618ffd5af16fa7c363b81260d6e7 (diff)
downloadlinux-9d3158f5cb11142d85c351fa0e0087ef95ac9cb8.tar.xz
ata: move sata_link_{debounce,resume}() to libata-sata.c
* move sata_link_{debounce,resume}() to libata-sata.c * add static inline for CONFIG_SATA_HOST=n case (only one, for sata_link_resume() is needed) Code size savings on m68k arch using (modified) atari_defconfig: text data bss dec hex filename before: 32816 572 40 33428 8294 drivers/ata/libata-core.o after: 32724 572 40 33336 8238 drivers/ata/libata-core.o Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/ata/libata-sata.c')
-rw-r--r--drivers/ata/libata-sata.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
index d66afdc33d54..34852fced999 100644
--- a/drivers/ata/libata-sata.c
+++ b/drivers/ata/libata-sata.c
@@ -197,6 +197,144 @@ void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
EXPORT_SYMBOL_GPL(ata_tf_from_fis);
/**
+ * sata_link_debounce - debounce SATA phy status
+ * @link: ATA link to debounce SATA phy status for
+ * @params: timing parameters { interval, duration, timeout } in msec
+ * @deadline: deadline jiffies for the operation
+ *
+ * Make sure SStatus of @link reaches stable state, determined by
+ * holding the same value where DET is not 1 for @duration polled
+ * every @interval, before @timeout. Timeout constraints the
+ * beginning of the stable state. Because DET gets stuck at 1 on
+ * some controllers after hot unplugging, this functions waits
+ * until timeout then returns 0 if DET is stable at 1.
+ *
+ * @timeout is further limited by @deadline. The sooner of the
+ * two is used.
+ *
+ * LOCKING:
+ * Kernel thread context (may sleep)
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int sata_link_debounce(struct ata_link *link, const unsigned long *params,
+ unsigned long deadline)
+{
+ unsigned long interval = params[0];
+ unsigned long duration = params[1];
+ unsigned long last_jiffies, t;
+ u32 last, cur;
+ int rc;
+
+ t = ata_deadline(jiffies, params[2]);
+ if (time_before(t, deadline))
+ deadline = t;
+
+ if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
+ return rc;
+ cur &= 0xf;
+
+ last = cur;
+ last_jiffies = jiffies;
+
+ while (1) {
+ ata_msleep(link->ap, interval);
+ if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
+ return rc;
+ cur &= 0xf;
+
+ /* DET stable? */
+ if (cur == last) {
+ if (cur == 1 && time_before(jiffies, deadline))
+ continue;
+ if (time_after(jiffies,
+ ata_deadline(last_jiffies, duration)))
+ return 0;
+ continue;
+ }
+
+ /* unstable, start over */
+ last = cur;
+ last_jiffies = jiffies;
+
+ /* Check deadline. If debouncing failed, return
+ * -EPIPE to tell upper layer to lower link speed.
+ */
+ if (time_after(jiffies, deadline))
+ return -EPIPE;
+ }
+}
+EXPORT_SYMBOL_GPL(sata_link_debounce);
+
+/**
+ * sata_link_resume - resume SATA link
+ * @link: ATA link to resume SATA
+ * @params: timing parameters { interval, duration, timeout } in msec
+ * @deadline: deadline jiffies for the operation
+ *
+ * Resume SATA phy @link and debounce it.
+ *
+ * LOCKING:
+ * Kernel thread context (may sleep)
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int sata_link_resume(struct ata_link *link, const unsigned long *params,
+ unsigned long deadline)
+{
+ int tries = ATA_LINK_RESUME_TRIES;
+ u32 scontrol, serror;
+ int rc;
+
+ if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
+ return rc;
+
+ /*
+ * Writes to SControl sometimes get ignored under certain
+ * controllers (ata_piix SIDPR). Make sure DET actually is
+ * cleared.
+ */
+ do {
+ scontrol = (scontrol & 0x0f0) | 0x300;
+ if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
+ return rc;
+ /*
+ * Some PHYs react badly if SStatus is pounded
+ * immediately after resuming. Delay 200ms before
+ * debouncing.
+ */
+ if (!(link->flags & ATA_LFLAG_NO_DB_DELAY))
+ ata_msleep(link->ap, 200);
+
+ /* is SControl restored correctly? */
+ if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
+ return rc;
+ } while ((scontrol & 0xf0f) != 0x300 && --tries);
+
+ if ((scontrol & 0xf0f) != 0x300) {
+ ata_link_warn(link, "failed to resume link (SControl %X)\n",
+ scontrol);
+ return 0;
+ }
+
+ if (tries < ATA_LINK_RESUME_TRIES)
+ ata_link_warn(link, "link resume succeeded after %d retries\n",
+ ATA_LINK_RESUME_TRIES - tries);
+
+ if ((rc = sata_link_debounce(link, params, deadline)))
+ return rc;
+
+ /* clear SError, some PHYs require this even for SRST to work */
+ if (!(rc = sata_scr_read(link, SCR_ERROR, &serror)))
+ rc = sata_scr_write(link, SCR_ERROR, serror);
+
+ return rc != -EINVAL ? rc : 0;
+}
+EXPORT_SYMBOL_GPL(sata_link_resume);
+
+/**
* sata_link_scr_lpm - manipulate SControl IPM and SPM fields
* @link: ATA link to manipulate SControl for
* @policy: LPM policy to configure