While most hardware will simply ignore a write to a read-only register,
some hardware will signal an abort if this occurs.
This commit introduces the flag AHCI_HFLAG_NO_WRITE_TO_RO to prevent the
AHCI library from attempting to write to the HOST_CAP, HOST_CAP2, and
HOST_PORTS_IMPL registers which may be read-only.
Signed-off-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
#endif
AHCI_HFLAG_WAKE_BEFORE_STOP = (1 << 22), /* wake before DMA stop */
AHCI_HFLAG_YES_ALPM = (1 << 23), /* force ALPM cap on */
+ AHCI_HFLAG_NO_WRITE_TO_RO = (1 << 24), /* don't write to read
+ only registers */
/* ap->flags bits */
/* Some registers might be cleared on reset. Restore
* initial values.
*/
- ahci_restore_initial_config(host);
+ if (!(hpriv->flags & AHCI_HFLAG_NO_WRITE_TO_RO))
+ ahci_restore_initial_config(host);
} else
dev_info(host->dev, "skipping global host reset\n");